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IntroductionGreetingsandwelcometotheunitonmagnetism.Ihopeyouwillfindthishelpfulinpreparingtoteachyourstudents.Itisexhaustivelythoroughincontentandawholelotoffun,becausethat’swhenstudentsandteachersdotheirbestwork.Youcanteachthiscourseimmediatelyfollowingthe12‐weekunitonElectricity.

Thiscurriculumcoursehasbeenpreparedtobecompletedoverseveralweeks,completing1‐2lessonsperweek.Youwillfindthatthereare23lessonsoutlinedtotakeyoufromanintroductionofmagnetismonthroughseveraladvancedprojectscomplexenoughtowinaprizeatthesciencefair(andI’vealsoincludedasampleofthisatthebackofthisbook).Ifyoucompletethiscourseandsendyourkidsoff,you’llfindtheirhighschoolteachersentirelyblownawaybytheirmasteryofthesubject.EachlessonhasaTeacherPageandaStudentWorksheet.

ThefollowingfeaturesareoneachsetoftheTeacherPages:

Overview:Thisisthemaingoalofthelesson. SuggestedTime:Makesureyouhaveenoughforcompletingthislesson. Objectives:Thesearethecoreprinciplescoveredwiththislesson. Materials:Gatherthesebeforeyoustart. LabPreparation:Thisoutlinesanypreparationyouneedtodoaheadoftime. Lesson:Thisoutlineshowtopresentthetopictothestudents,stirsupinterestandgetsthemmotivatedto

learnthetopic. LabTime&Worksheets:Thisincludesactivities,experiments,andprojectsthatreinforcetheconceptsand

reallybringsthemtolife.You’llalsofindworksheetsthatmakeuptheirScientificJournal. BackgroundLessonReading:Thisisoptionaladditionalreadingmaterialyoucanutilizeaheadoftimeto

helpyoufeelconfidentwhenthestudentsaskquestionsduringtheLabTime.Idon’trecommendgivingthisreadingtothekidsbeforehand.Ifyoumustshareitwiththem,thendosoafterthestudentshavegottenachancetorollaroundwiththeactivities.Doingthisteacheskidstoasktheirownquestionsbygettingcuriousabouttheconceptsthroughtheexperiments,thewayrealscientistsdointherealworld.

Exercises&AnswerKey:Howwelldidyouteach?Howwelldidtheylearn?Timetofindout. Closure:Beforemovingon,askyourstudentsiftheyhaveanyrecommendationsorunansweredquestions

thattheycanworkoutontheirown.Brainstormingextensionideasisagreatwaytoaddmoresciencestudiestoyourclasstime.

ImmediatelyfollowingtheTeacherPagesare“StudentWorksheets”foreachoftheactivities.Eachsetofstudentworksheetshasthefollowingsections:

Overview WhattoLearn Materials LabTime&Worksheets Exercises

Inadditiontothelessons,wehavealsopreparedthefollowingitemsyou’llfinduseful:

ScientificMethodGuide MasterMaterialsandEquipmentList LabSafetySheet

WrittenQuiz(withAnswerKey)

LabPracticalTests(withAnswerKey) ScienceFairProjectSampleReport

MasterMaterialsListforAllLabsThisisabrieflistofthematerialsthatyouwillneedtodoalloftheactivities,experimentsandprojectsineachsection.Thesetofmaterialslistedbelowisjustforonelabgroup.Ifyouhaveaclassof10labgroups,you’llneedtoget10setsofthematerialslistedbelow.For10labgroups,aneasywaytokeeptrackofyourmaterialsistogiveeachgroupanumberfrom1to10,andmakeup10separatelabkitsusingsmallplastictubsorbaskets.Putonenumberoneachitemandfilleachtubwiththematerialslistedbelow.Labelthetubswiththesectionname,likeMagnetismStudyKit,andyouwillhaveaneasywaytokeeptrackofthematerialsandbuildaccountabilityintotheprogramforthekids.Copytheselistsandsticktheminthebinforeasytracking.Feelfreetoreuseitemsbetweenlessonsandunitsections.Mostmaterialsarereusableyearafteryear.

MaterialsforStandardLabs 9Vbatterywithclip(RS#270‐325) AAbatteries(2) AAcase(RS#270‐408) Alligatorwires(RS#278‐1157) Bi‐polarLED(RS#276‐012) Chopstick Compass Donutmagnet(RS#64‐1888) Foamblocks Hairdryer Hammer Hobbymotor,9‐18VDC(RS#273‐256) Hotgluegun Insulatedwire(1foot) LED(RadioShack(RS)#276‐012) Magnetwire(RS#278‐1345) Magnets(RS#64‐1883) Metalscrews(5differentsizes) Nails(92‐3incheslong) Needleorpin Paperclip Plasticfork Propeller Rectangularmagnet(RS#64‐1879) Reedswitch(www.sparkfun.com) Relay(RS#275‐206) Rubbereraser Ruler Sandpaper Shallowdishorpietin Smallpieceoffoam(likeapackingpeanut) Straw

String Tape Toiletpaperorpapertoweltube

MaterialsforAdvancedLabs

Aluminumblock(thethickerthebetter) Babyoilorvegetableoil Candle(withadulthelp) Cleanglassjarwithlid Disposableplasticcupwithlid Glovesandgoggles Laserpointer(cheapkey‐chainworkwell) Magnet,tinybead(www.KJmagnetics.com

R211) Magnets,4donut(RS#64‐1888) Magnet,largeceramic(RS#64‐1877) Medicinedropper Metalboltwithnutandlargewasher Mirrors(2small) Neodymiummagnets,four½”

(www.KJmagnetics.comB888) Oldtonercartridgefromalaserprinteror

copymachine Paperornewspaper Penorstraw Plasticbag Popsiclestick Rareearthmagnets,2(RS#64‐1895) Rubberbands(8) Steelballbearings,9(1/2”or5/8”) Thincopperwire Thread Woodorplasticrulerwithagroovedownthe

center,12”long Woodenspring‐typeclothespin

TABLEOFCONTENTSIntroduction...............................................................................................................................................................................................................2

MasterMaterialsListforAllLabs.....................................................................................................................................................................3

UnitPrep.....................................................................................................................................................................................................................6

LabSafety...................................................................................................................................................................................................................7

TeachingScienceRight.........................................................................................................................................................................................8

EducationalGoals..................................................................................................................................................................................................10

Lesson#1:What’sMagnetic?...........................................................................................................................................................................13

Lesson#2:BreakingMagnets..........................................................................................................................................................................22

Lesson#3:WhichWayisNorth?....................................................................................................................................................................26

Lesson#5:BouncingMagnets.........................................................................................................................................................................34

Lesson#7:MagneticSensors...........................................................................................................................................................................44

Lesson#9:CurieHeatEngine..........................................................................................................................................................................54

Lesson#10:LinearAccelerator......................................................................................................................................................................59

Lesson#11:EarthPulse.....................................................................................................................................................................................69

Lesson#12:Ferrofluid........................................................................................................................................................................................76

Lesson#13:BrakingMagnets..........................................................................................................................................................................80

MagnetsEvaluation..............................................................................................................................................................................................86

MagnetsQuiz...........................................................................................................................................................................................................89

MagnetsLabPractical..........................................................................................................................................................................................92

Lesson#14:Galvanometers..............................................................................................................................................................................94

Lesson#15:Electromagnets.........................................................................................................................................................................101

Lesson#16:MotorsandGenerators..........................................................................................................................................................107

Lesson#17:Quick‘n’EasyDCMotor.........................................................................................................................................................114

Lesson#18:HomemadeRelayShockers..................................................................................................................................................118

Lesson#19:RelaysandTelegraphs...........................................................................................................................................................125

Lesson#20:DCMotor......................................................................................................................................................................................131

Lesson#21:HearingMagnetism.................................................................................................................................................................136

Lesson#22:RailAccelerator.........................................................................................................................................................................142

Lesson#23:HomemadeSpeakers..............................................................................................................................................................147

ElectromagnetismEvaluation.......................................................................................................................................................................153


ElectromagnetismQuiz....................................................................................................................................................................................155

ElectromagnetismLabPractical..................................................................................................................................................................157

SampleProject:LinearAccelerator............................................................................................................................................................158

TheScientificMethod.......................................................................................................................................................................................183

VocabularyfortheUnit.................................................................................................................................................................................185


UnitPrep

Thisisashortlistofthingsthatyoumaywanttoconsiderasyouprepareforthisunit.

StudentLabBooksIfyou’rethekindofteacherwholikestopreparelabbooksforyourkids,nowisagoodtimetodothis.YoucancopytheIntroductionforKidsandtheStudentWorksheetsforeachoftheexperiments,3‐holepunchthem,andsticktheminbinders.You’llwantonebinderperstudent.

ScienceJournalsOneofthebestthingsyoucandowithyourstudentsistoteachthemhowtotakenotesinajournalasyougoalong.Thisisthesamewayscientistsdocumenttheirownfindings,andit’salotoffuntolookbackatthesplatteredpageslateronandseehowfaryou’vecome.Ialwaysjotdownmyquestionsthatdidn’tgetansweredwiththeexperimentacrossthetopofthepagesoIcanresearchthesetopicsmore.

MasterSetofMaterialsIfyouplanondoingallthelabsinthisunit,you’llwanttostartgatheringyourmaterialstogether.There’samastermaterialslistsoyou’llhaveeverythingyouneedwhenyouneedit.

TestCopiesStudentswilltaketwotestsattheendofeachsection.Therearequizzesandlabpracticaltestsyoucancopyandstashawayforwhenyouneedthem.

ClassroomDesignAsyouprogressthroughtheunits,you’llbemakingdemosoftheexperimentsandkidswillbemakingposters.Youcanhangtheseuponyourbulletinboards,stringthemfromtheceiling,ordisplaytheminauniqueway.Ialwaysliketosnapphotosofthekidsdoingtheirexperimentsandhangthoseupalongwiththeirbestlabssotheycanseetheirprogressaswegoalong.


LabSafety

Gogglesshouldbewornwhenworkingwithchemicals,heat,fire,orprojectiles.Thisprotectsyoureyesfromchemicalsplatter,explosions,andtinyfast‐movingobjectsaimedattheeyes.Ifyouwearglasses,youcanfindgogglesthatfitoverthem.Don’tsubstituteeyeglassesforgoggles,becausegogglesprovidesideprotectionthatglassesdon’t.

CleanupMessesYourlabareashouldbeneat,organized,andspotlessbeforeyoustart,duringyourexperiment,andwhenyouleave.Scientistswastelotsoftimehuntingforlostpapers,findingpiecesofanexperiment,andtryingtorepositionsensitiveequipment…allofwhichcouldhaveeasilybeenavoidedhadtheybeentaughttheseskillsfromthestart.

DisposeofPoisonsIfapoisonoussubstancewasused,created,orproducedduringyourexperiment,youmustfollowtheproperhandlingproceduresfordisposal.You’llfinddetailsforthisinexperimentsasappropriate.

SpecialNotesonBatteriesDonotusealkalinebatterieswithyourexperiments.Findthesuper‐cheapkindofbatteries(usuallylabeled“HeavyDuty”or“SuperHeavyDuty”)becausethesetypesofbatterieshaveacarbon‐zinccore,whichdoesnotcontaintheacidthatalkalinebatterieshave.Thismeanswhenyourstudentswireupcircuitsincorrectly(whichyoushouldexpectthemtodobecausetheyarelearning),thecircuitswillnotoverheatorleak.Ifyouusealkalinebatteries(likeEnergizerandDuracell)andyourstudentsshortacircuit,theirwiresandcomponentswillgetsuper‐hotandleakacid,whichisverydangerous.

NoEatingorDrinkinginLabAllfoodsanddrinksarebannedfromyourclassroomduringscienceexperimentation.Whenyoueatordrink,youruntheveryrealriskofingestingpartofyourexperiment.Forelectricityandmagnetismlabs,alwayswashyourhandsafterthelabisovertorinseofftheleadfromtheelectricalcomponents.

NoHorsePlayWhenyougoofaround,accidentshappen,whichmeanschemicalsspill,circuitsshort,andallkindsofhazardscanoccurthatyouweren’texpecting.Neverthrowanythingtoanotherpersonandbecarefulwhereyouputyourhands–itcouldbeinthemiddleofasensitiveexperiment,especiallywithmagnetismandelectricity.Youdon’twanttoruntheriskofgettingshockedorelectrifiedwhenit’snotpartofyourexperiment.

FireIfyouthinkthere’safireintheroom(evenifyou’renotsure),letyourteacherknowrightaway.Iftheyarenotaround(theyalwaysshouldbe),smotherthefirewithafireblanketoruseafireextinguisherandsendsomeonetofindanadult.Stop,drop,androll!

QuestionsIfyou’renotsureaboutsomething,stopandask,nomatterwhatit’sabout.Ifyoudon’tknowhowtoproperlyhandleachemical,dopartofanexperiment,ask!Ifyou’renotcomfortabledoingpartoftheexperiment,thendon’tdoit.


TeachingScienceRightTheseactivitiesandexperimentswillgiveyouatasteofhowsciencecanbetotallycoolANDeducational.Butteachingscienceisn’talwayseasy.There’salotmoretoitthanmosttraditionalsciencebooksandprogramsaccomplish.Ifyourstudentsdon’trememberthesciencetheylearnedlastyear,youhaveaproblem.

Whatdokidsreallyneedtoknowwhenitcomestoscience?Kidswhohaveasolidscienceandtechnologybackgroundarebetterequippedtogotocollege,andwillhavemanymorechoicesoncetheygetoutintotherealworld.

Learningscienceisn’tjustamatterofmemorizingfactsandtheories.Onthecontrary,it’sdevelopingadeepcuriosityabouttheworldaroundus,ANDhavingasetoftoolsthatletskidsexplorethatcuriositytoanswertheirquestions.Teachingscienceinthiswayisn'tjustamatterofputtingtogetheratextbookwithafewscienceexperimentsandkits.

Scienceeducationisathree‐stepprocess(andImeanteachingscienceinawaythatyourstudentswillreallyunderstandandremember).Herearethesteps:

1.Getkidsgenuinelyinterestedandexcitedaboutatopic.

2.Givethemhands‐onactivitiesandexperimentstomakethetopicmeaningful.

3.Teachthesupportingacademicsandtheory.

Mostsciencebooksandcurriculumjustfocusonthethirdstepandmaythrowinanexperimentortwoasanafterthought.Thisjustisn’thowstudentslearn.Whenyouprovideyourstudentswiththesethreekeys(inorder),youcangivethemthekindofscienceeducationthatnotonlyexcitesthem,butthattheyrememberformanyyearstocome.

Sowhatdoyoudo?First,don’tworry.It’snotsomethingthattakesyearsandyearstodo.Itjusttakescommitment.

Whatifyoudon’thavetime?WhatI’mabouttodescribecantakeabitoftimeasateacher,butitdoesn’thaveto.Thereisawaytoshortcuttheprocessandgetthesameresults!ButI’lltellyoumoreaboutthatinaminute.First,letmetellyouhowtodoittherightway:

PuttingItintoAction

Stepone:Getstudentsgenuinelyinterestedandexcitedaboutatopic.Startbydecidingwhattopicyouwantyourstudentstolearn.Then,you’regoingtogetthemreallyinterestedinit.Forexample,supposeIwantmyfifth‐gradestudentstolearnaboutaerodynamics.I’llarrangeforthemtowatchavideoofwhatit’sliketogoupinasmallplane,orevenfindsomeonewhoisapilotandcancometalkwiththekids.Thisisthekindofexperiencethatwillreallyexcitethem.

Steptwo:Giveyourstudentshands‐onactivitiesandexperimentstomakethetopicmeaningful.ThisiswhereItakethatexcitementandletthemexploreit.Ihaveflyinglessonvideos,airplanebooks,andrealpilotsinteractingwithmystudents.I’llalsoshowvideosonhowpilotsplanforaflight.Mystudentswilllearnaboutnavigation,figuringouthowmuchfuelisneededfortheflight,howtheweighttheplanecarriesaffectstheaerodynamicsofit,andsomuchmore.(AnddidIjustseeaspotforafuturemathlessonalso?)I’llusepilottrainingvideostohelpusfigurethisout(shortofalivedemo,avideoisincrediblypowerfulforlearningwhenusedcorrectly).


Mystudentsareincrediblyexcitedatthispointaboutanythingthathastodowithairplanesandflying.Theyareallpositivetheywanttobepilotssomedayandarealreadywantingflyinglessons(remember‐theyareonlyfifth‐graders!).

Stepthree:Teachthesupportingacademicsandtheory.Nowit’stimetointroduceacademics.Honestly,Ihavemypickofsomanytopics,becauseflyingincludessomanydifferentfields.Mystudentsuseanglesandmathinflightplanning,mechanicsandenergyinhowtheengineworks,electricityinalltheequipmentonboardtheplane,andofcourseaerodynamicsinkeepingtheplaneintheair(tonamejustafew).

I’mgoingtousethisasthefoundationtoteachtheacademicsideofallthetopicsthatareappropriate.Westartwithaerodynamics.Theylearnaboutliftanddrag,makepaperandbalsa‐woodglidersandexperimentbychangingdifferentparts.Theycalculatehowbigthewingsneedtobetocarrymoreweight(jellybeans)andthentrytheirmodelswithbiggerwings.Thenwemoveontothegeometryusedinnavigation.Insteadofdrawinganglesonablanksheetofpaper,ourworkspaceismadeofairplanemaps(freefromtheairport).We’reactuallyplanningpartofthenextflightmystudentswill“take”duringtheirgeographylesson.Suddenly,anglesarealotmoreinteresting.Infact,itturnsoutthatweneedabitoftrigonometrytofigureoutsomethings.

Ofcourse,a10‐year‐oldcan’tdotrigonometry,right?Wrong!Theyhavenoideathatit’susuallyforhighschoolandlearnaboutcosinesandtangents.Throughoutthis,I’mgivingthemchancestotalkwiththepilotinclass,sharewhatthey’velearnedwitheachother,andevenplanarealflight.Howcoolisthattoakid?

Thekeyistofocusonbuildinginterestandexcitementfirst,thentheacademicsareeasy.Trystartingwiththeacademicsand...well,we’veallhadtheexperienceoftryingtogetkidsdosomethingtheydon’treallywanttodo.

TheShortcutOK,sothismightsoundlikeit’stime‐intensive.Ifyou’rethinking,“Ijustdon’thavethetimetodothis!”ormaybe,“Ijustdon’tunderstandsciencewellenoughmyselftoteachittomystudentsatthatlevel.”Ifthisisyou,you’renotalone.

Thegoodnewsis,youdon’thaveto.Theshortcutistofindsomeonewhoalreadyspecializesintheareayouwantyourstudentstolearnaboutandexposethemtotheexcitementthatthepersongetsfromthefield.Then,insteadofyoubeingtheonetoinventanentirelynewcurriculumofhands‐onactivitiesandtheacademics,useasolidscienceprogramorcurriculum(livevideos,notcartoons).Thiswillprovidethemwithboththehands‐onexperimentsandtheacademicbackgroundtheyneed.

Ifyouuseaprogramthatisself‐guided(thatis,itguidesyouandyourstudentsthroughitstep‐by‐step),youdon’tneedtobehassledwiththepreparation.That’swhatthisunitisintendedtodoforyouandyourstudents.Thisprogramusesthesecomponentsandmatchesyoureducationalgoalssetbystatestandards.

Thisunitimplementsthethreekeystepswejusttalkedaboutanddoesthisforyou.Myhopeisthatyounowhavesomenewtoolsinyourteachingtoolboxtogiveyourstudentsthebeststartyoucan.Iknowit’slikeawildrollercoasterridesomedays,butIalsoknowit’sworthit.Havenodoubtthatthatthecaringandattentionyougivetoyourstudents’educationtodaywillpayoffmanytimesoverinthefuture.


EducationalGoalsThescientificprincipleswe’regoingtocoverwerefirstdiscoveredbyahostofscientistsinthe19thcentury,eachworkingontheideasfromeachother,mostprominentlyJamesMaxwell.Thisisoneofthemostexcitingareasofscience,becauseitincludesoneofthemostimportantscientificdiscoveriesofalltime:howelectricityandmagnetismareconnected.Beforethisdiscovery,peoplethoughtofelectricityandmagnetismastwoseparatethings.Whenscientistsrealizedthatnotonlyweretheylinkedtogether,butthatonecausestheother,thefieldofphysicsreallytookoff.

Herearethescientificconcepts:

Magnets

Magneticfieldsarecreatedbyelectronsmovinginthesamedirection.Electronscanhavea“left”or“right”spin.Ifanatomhasmoreelectronsspinninginonedirectionthanintheother,thatatomhasamagneticfield.

Ifanobjectisfilledwithatomsthathaveanabundanceofelectronsspinninginthesamedirection,andifthoseatomsarelinedupinthesamedirection,thatobjectwillhaveamagneticforce.

Afieldisanareaaroundanelectrical,magneticorgravitationalsourcethatwillcreateaforceonanotherelectrical,magneticorgravitationalsourcethatcomeswithinthereachofthefield.

Infields,theclosersomethinggetstothesourceofthefield,thestrongertheforceofthefieldgets.Thisiscalledtheinversesquarelaw.

Amagneticfieldmustcomefromanorthpoleofamagnetandgotoasouthpoleofamagnet(oratomsthathaveturnedtothemagneticfield.)

Allmagnetshavetwopoles.Magnetsarecalleddipolar,whichmeanstheyhavetwopoles.Thetwopolesofamagnetarecallednorthandsouthpoles.Themagneticfieldcomesfromanorthpoleandgoestoasouthpole.Oppositepoleswillattractoneanother.Likepoleswillrepeloneanother.

Ironandafewothertypesofatomswillturntoalignthemselveswiththemagneticfield.Overtime,ironatomswillalignthemselveswiththeforceofthemagneticfield.

TheEarthhasahugemagneticfield.TheEarthhasaweakmagneticforce.ThemagneticfieldcomesfromthemovingelectronsinthecurrentsoftheEarth’smoltencore.TheEarthhasanorthandasouthmagneticpolewhichisdifferentfromthegeographicNorthandSouthPole.

Compassesturnwiththeforceofthemagneticfield.

Electromagnetism

Magnetismiscausedbymovingelectrons. Electricityismovingelectrons. Electricitycausesmagnetism. Movingmagneticfieldscancauseelectronstomove. Electricitycanbecausedbymovingmagneticfields.


Electricityisaflowofelectrons. Aflowofelectronscreatesamagneticfield. Magneticfieldscancauseaflowofelectrons. Magneticfieldscancauseelectricity.

Bytheendofthelabsinthisunit,studentswillbeableto:

Buildasimplecompassanduseittodetectmagneticeffects,includingEarth’smagneticfield. Understandhowelectriccurrentsproducemagneticfields. Knowhowtobuildanduseanelectromagnet. Constructelectricmotors,electricgenerators,andsimpledevices,suchasdoorbellsandearphones. Understandthatmagnetshavetwopoles(northandsouth)andthatlikepolesrepeleachotherwhile

unlikepolesattracteachother. Differentiateobservationfrominference(interpretation)andknowscientists’explanationscome

partlyfromwhattheyobserveandpartlyfromhowtheyinterprettheirobservations. Measureandestimatetheweight,length,orvolumeofobjects. Formulateandjustifypredictionsbasedoncause‐and‐effectrelationships. Conductmultipletrialstotestapredictionanddrawconclusionsabouttherelationshipsbetween

predictionsandresults. Constructandinterpretgraphsfrommeasurements.

Followasetofwritteninstructionsforascientificinvestigation.


MAGNETS

WhatISmagnetism,anyway?Youcanfeelhowtwonorthsidesofamagnetpushagainsteachotherwhenyoubringmagnetsclosetogether,butwhatISthatinvisibleforce,andwhyisitthere?Andhowcomemagnetssticktothefridgeandnotasodacan,eventhoughbotharemagnetic?Andwhenyourunmagnetsdownametalramp,theydefygravityandbraketoastop.Andhowcomethegrapesfromyourlunchboxtwistaroundtoalignwithmagnets,eventhoughthere’snoironinside?There’sgottobeareasonbehindthismadness…wouldyouliketofindoutwhatitiswithme?

We’reabouttodivedeeplyintothemysteriousworldofmagnetism.Althoughscientistsarestilltryingtopuzzleoutsomeofitssecrets,I’mgoingtogetyouuptospeedonwhattheydoknowtoday.


Lesson#1:What’sMagnetic?TeacherSection

Overview:Studentswillgrabamagnetandmovearoundtheroomtryingtofigureoutwhat’sspecialabouttheobjectsthatsticktoit.Therearetwodatasheetstheywillfilloutintheirquest.

SuggestedTime:30‐45minutes

Objectives:Todiscovernotonlywhat’smagnetic,butalsowhatspecifickindsofobjectsaremagnetic.Magneticfieldsarecreatedbyelectronsmovinginthesamedirection.Electronscanhavea“left”or“right”spin.Ifanatomhasmoreelectronsspinninginonedirectionthanintheother,thatatomhasamagneticfield.Ifanobjectisfilledwithatomsthathaveanabundanceofelectronsspinninginthesamedirection,andifthoseatomsarelinedupinthesamedirection,thatobjectwillhaveamagneticforce.

Materials(perlabgroup)

1rectangularmagnet 1circulardiskmagnet

LabPreparation

1. Printoutcopiesofthestudentworksheets.2. Optionalbuthighlyrecommended,sinceitcoversthebasicsforthisentiresection:Readoverthe

BackgroundLessonReadingbeforeteachingthisclass.3. Identifyseveraldozenobjectsinyourroomthataremagneticsoyouarepreparedifthekidsneedalittle

help.4. Watchthevideosoyoucandemothismagneticexperimentforthekids.Thisisn’ttheexperimenttheyare

doinginclasstoday,butratheroneforhomeworkbeforenexttime.

BackgroundLessonReading

WhatCausesMagnetism?Believeitornot,electrons!Thosewackylittlefellowsthatwelearnedaboutseverallessonsagoarethekeytomagnetism.Asyoumovefurtherandfurtherinyourscienceeducation,you’llnoticethatelectronsareresponsibleforalotofstuffthatgoesoninscience!

Moreaccurately,amajorityofelectronsmovinginasimilardirectioncreatesamagneticfield.Thisishowelectromagnetswork.Electronsareforcedtomovethroughawireandthemovingelectronscauseamagneticfield.(We’lllookdeeperintomagneticfieldsinafuturelesson.)

“Buthowareelectronsmovinginmymagnetonmyfridge?Itisn’tconnectedtoanybattery.What’sgoingonthere!?Don’tIneedelectricitytohavemovingelectrons?”

Electromagnetsdohaveelectricityflowingthroughthem.Electricityisnothingmorethanmovingelectrons.Soit’stheelectricitythatcausesthemagneticforceinelectromagnets.

However,mostofthemagnetsyourunacrossarenotattachedtoanyformofelectricity.Sohowaretheelectronsmoving?


Electronsmoveontheirown.Theymovearoundthenucleusandtheyspin.It’stheelectronspinthattendstoberesponsibleforthemagneticfieldinthose“permanent”magnets(themagnetsthatmaintainamagneticfieldwithoutelectricityflowing).

“Butdon’telectronsalwaysspin?Shouldn’teverythingbemagnetic?”

Yes,electronsarealwaysspinning.Thereasonsomethingsaremagneticandotherthingsaren’tisthebalanceofthespinningelectrons.

Electronsaresaidtospinleftorright.It’snotquitethatsimplebutitmakesiteasiertothinkandtalkabout.Mostatomshaveafairlyevennumberofleftandrightspinningatoms.Ifthere’sfourspinningleft,there’sfourspinningright.Ifthere’sninespinningright,there’seightspinningleft.Sincetheyarefairlybalanced,there’snonetdirectioninwhichtheelectronsaremoving.Withnooveralldirectionofmovementthere’snomagneticforce.

However,thereareafewatoms,ironbeingthemostfamous,thatarenotinbalance.Ironhasfourmoreelectronsthatspininonedirectionthanintheother.Thisexcessofsamespinningelectronscreatesanetdirectionalmovementandthusamagneticforce!Nickelandcobaltareotherfairlycommonmagneticmetals.

“Aha,soeverythingthat’smadeofironismagnetic!Gotit.”

Well,notsofast.Yes,eachironatomislikealittlemagnet,butnotallironobjectshaveamagneticfield.Infact,mostdon’t.Thereasonthatmostobjectsthathaveironinthemarenotmagneticisbecausetheatomsarealljumbledup.

ImagineIgaveyouashoeboxfilledwithsmallmagnets.SinceIjustthrewthemagnetsinthere,theyarealljumbledup.Somearefacingright,someleft,someupandsomedown.Becauseofthejumble,thewholeboxmaynothavemuchmagneticforcesincethemagnetsinsideareallcancelingeachotherout.

Now,imaginewhatwouldhappenifthemagnetsinsidetheboxdidallfacethesameway.IfIstuckthemallendtoendandcreatedalongstringofmagnets.Nowtheboxwouldhaveaverypowerfulmagneticforce,right?Thisisthedifferencebetweenanironnailandamagnet.Thenailhasironatomsgoingeverywhichway,whilethemagnethasironatomsthatarefairlylinedup.Themorelineduptheironatomsare,thestrongerthemagneticforce.

Diamagneticmaterials(likebismuth,water,andgraphite)haveveryweakmagneticfields.Whentheelectronshaveaboutthesamenumberspinningleftandspinningright,theycanceleachotheroutandtheatomhasnomagneticpoles.However,ifyoubringamagnetnear,themagneticfieldcausestheindividualelectronsintheatomtomove,andsincemovingelectronscreateamagneticfields,theelectronscreateamagneticfieldoppositetotheoriginalmagneticfieldandtheatommovesawayfromthemagnet.Theeffectisveryweak,butwithenoughcareyoucanseethiseffectinwater(whichiswhatagrapeismostlymadeupof).

Paramagneticmaterials(likealuminum,helium,andplatinum)needtobechilledinorderfortheirmagneticfieldstobenoticeable.Here'swhy:Whatiftheatomhasmoreelectronsspinningleftthanright?Whenthishappens,theatomnowhasmagneticpoles(northandsouth),andyoucanthinkofeachatomlikealittlemagnet.However,thesemagnetsarenotalllinedupinthesamedirection,sotheiroverallmagneticeffectcancelsout.Ifyoubringinamagnet(orplacetheatomsinamagneticfield),theatomsstarttolineupinthesamedirectionandthematerialstartstobecomemagnetized.Itdoesn’thappenquicklyoreasily,becausetheatomsstillhavesomuchenergythattheykeepbouncingaround,evenwheninasolidstate.Sotomagnetizesomethingquickly,youneedtobringdownthetemperaturetoreducethemotionoftheatomstogetthemtoreallylineup.Paramagneticmaterialsareattractedtobothendsofamagnet.


Ferromagneticmaterialsarethefourelements(iron,nickel,cobalt,andgadolinium)thatmostpermanentmagnetsaremadeupof.Theseatomsstaylineduptogetherevenwhentheyareattemperaturesthatwouldcauseotheratomstobounceoutofalignment.Themagneticeffectsaremostlycausedbytheinnermostelectronsintheinnerorbits,whichallalignedthesameway,andcontributethemagneticfield.Someparamagneticmaterials(likechromiumandmanganese)haveatomsthatpairupandcanceleachotherout.Thenorthpoleofoneatomwilllineupwiththesouthpoleofanother.

Lesson

1. Whilethekidsarefilingin,writethisontheboard:

Isticktosomethingsbutnottoothers.IstickbutI’mnotsticky.Iattractsomethings,butpushotherthingsaway.Ifallowedtomove,Iwillalwayspointthesameway.WhatamI?

2. Well,sinceyouknowthetopicofthislessonthisisn’tthehardestriddletosolve.“I’m”amagnetright?Sure.Tellthekidsthattodaywe’regoingtotakealookatthewackythingsamagnetdoes:Itsticksbutit’snotsticky.Itonlystickstocertainthings,anditpushessomethingsaway.Ifyouhangitfromastringorfloatitinwater,itwillalwayspointnorth.Ifthat’snotenoughstrangeness,aswe’llfindoutinalaterlesson,magnetscanactuallycreateelectricity.Wow,whatawackythingamagnetis!

3. Askthekids:“Whatisamagnet?”Startthemoffbyaskingthemwheretheythinkmagnetismcomesfromintheformofadiscussion.Youcansparktheirimaginationsbyaskingthesequestions:

a. Whydoesamagnetsticktoyourfridgeandnotyoursodacan,eventhoughbotharemetal?(Thecanisactuallyparamagnetic,whichwewilltalkmoreaboutlater.)

b. Areallmagnetsmadeofmetal?(Someareceramicorbendylikeplastic.)c. Thebreakfasttheyatethismorningwasprobablyalsomagnetic…whatdotheythinkitwas?

(Cerealfortifiedwithiron.Watchthevideoanddemothiseffect.Youcanhavethekidsdothisathomeforhomeworkfortomorrow.)

4. Announcetothekidsthattodaytheyaregoingtobemagneticdetectivesasyourunthelab.Theirjobistofindwhatkindsofobjectsaremagnetic.

LabTime

1. Reviewtheinstructionsontheirworksheetsandthenbreakthestudentsintotheirlabgroups.Handeachgrouptheirmaterials.

2. Havethekidsrunaroundtheroomwiththeirmagnetsandtestseveraldifferentobjectstoseeifthemagnetstickstoit.Thekidswillfillouttheirdatasheetastheygoalong,ordoitaftertheyracearoundtestingdifferentobjects(yourchoice).

3. Afterthey’vecompletedthefirstdatatable,askforshares.Whatdidtheyfindthatismagnetic?Writedowntheiranswersontheboardinalistforeveryonetosee.Youshouldnothaveanyitemsthatarenotmetalinyourlist.

4. Askthemtotestthematerialsonthelistandidentifywhatkindofmetaltheyare.Theywillwritethisintheseconddatatable.Inyourclassroom,youshouldbeabletofindbrass,tin,aluminum,silver,gold(ifyou’rewearingjewelryandtheyarecareful),steel,iron,tin…etc.


5. Regroupandaskthekidsifthere’sapattern.Whatkindsofmetalaremagnetic?(Youshouldonlyfindthatiron,nickel,andcobaltaremagnetic.)

Exercises

1. Whichobjectsareattractedtothemagnet?(Objectscontainingiron,nickel,cobalt,orgadolinium)2. Areallmetalobjectsattractedtothemagnet?(No.See#1above)3. Doestheshapeofthemagnetmatter?(No,butwe’llexplorewherethepolesareondifferentmagnetsnext

time.)4. Arethingsattractedtothemagnetiftheyhavetopassthroughsomethingthatisn’t,likeapieceofpaper?

(Yes–magneticforcecantravelthroughmaterialsthatarenotattractedtothemagnet.)

ClosureBeforemovingon,askyourstudentsiftheyhaveanyrecommendationsorunansweredquestionsthattheycanworkoutontheirown.Brainstormingextensionideasisagreatwaytoaddmoresciencestudiestoyourclasstime.


Lesson#1:What’sMagnetic?StudentWorksheet

Name______________________________________________________________________

Overview:Greetingsandwelcometothestudyofmagnetism!Thisfirstlessonissimplytogetyoutoplaywithmagnetsanddecidewhatitisthatyouwanttolearnaboutmagnetismsowecandothereallycoolstufflateron.

WhattoLearn:Yourjobistodiscovernotonlywhat“magnetic”means,butalsowhatspecifickindsofobjectsaremagnetic.Magneticfieldsarecreatedbyelectronsmovinginthesamedirection.Electronscanhavea“left”or“right”spin.Ifanatomhasmoreelectronsspinninginonedirectionthanintheother,thatatomhasamagneticfield.Ifanobjectisfilledwithatomsthathaveanabundanceofelectronsspinninginthesamedirection,andifthoseatomsarelinedupinthesamedirection,thatobjectwillhaveamagneticforce.

Materials

1rectangularmagnet 1circulardiskmagnet

LabTime

1. Whentheteacherletsyouloose,youaretomovearoundtheroomwithyourmagnetandtestseveraldifferentobjectstoseeifthemagnetstickstothem.Filloutthedatasheetasyougoalong,ordoitafteryou’vetestedyourdifferentobjects(teacher’schoice).


Object What’sitmadeof? Doesitsticktothemagnet?


2. Afteryou’vecompletedthefirstdatatable,sitbackdownbecauseit’stimeforshares.Whatdidyoufindthatismagnetic?

3. Nowmovearoundagainandtestthematerialsonthelistontheboardandidentifywhatkindofmetaltheyare.Writeyourobservationsthisintheseconddatatable.Checktoseeifyourteacheriswearingmetal.

What’sMagnetic?DataTable

MetalObject Whatkindofmetalisit? Doesitsticktothemagnet?

4. Sitbackdownandseeifthere’sapatterninwhatyoufound.Whatkindsofmetalaremagnetic?Writeit

here:

_________________________________________________________________________________________________________

_________________________________________________________________________________________________________

_________________________________________________________________________________________________________


Whataretenpossibleusesformagnetism?

1. 2. 3. 4. 5.

6. 7. 8. 9. 10.

Whatisonethingaboutmagnetismthatyounowknowbutdidn’tbeforeyouwalkedintoclass?

_________________________________________________________________________________________________________

_________________________________________________________________________________________________________

_________________________________________________________________________________________________________

Writedownthreethingsyoureallywanttoknowaboutmagnetism.

1.

2.

3.


ExercisesAnswerthequestionsbelow:

1. Whichobjectsareattractedtothemagnet?

2. Areallmetalobjectsattractedtothemagnet?

3. Doestheshapeofthemagnetmatter?

4. Arethingsattractedtothemagnetiftheyhavetopassthroughsomethingthatisn’t,likeapieceofpaper?

5. Thisevening,findanarticleorstorythatdescribeshowmagnetismimprovesourlives.Bringthearticletoschool.Ifyoubringinanarticlethatnooneelsebringsin,yougetextrapoints.


Lesson#2:BreakingMagnetsTeacherSection

Overview:Allmagnetshavetwopoles.Magnetsarecalleddipolar,whichmeanstheyhavetwopoles.Thetwopolesofamagnetarecallednorthandsouthpoles.Themagneticfieldcomesfromthenorthpoleandgoestothesouthpole.Oppositepoleswillattractoneanother.Likepoleswillrepeloneanother.


Objectives:Studentswillinvestigatethepolesofamagnetandgetcomfortablewiththeideathatthetwopolesareabsolutelyinseparable.


2rectangularmagnets 1circularmagnet Hammertobreakamagnet

LabPreparation

1. Printoutcopiesofthestudentworksheets.2. ReadovertheBackgroundLessonReadingbeforeteachingthisclass.3. Watchthevideoforthisexperimenttoprepareforteachingthisclass.


Didyouknowthatifyoucutamagnetinhalftotrytoseparatethenorthpolefromthesouthpole,you’llwindupwithtwomagnets,eachwiththeirownnorthandsouthpoles?Turnsoutthatthepolesareimpossibletoseparate!Notonlythat,butifyoutrytopuzzle‐piecethemagnetbacktogether,theinterlockingsectionsnowrepeleachother,notattract.Nowit’stimetodiscoverwhichpartoftheatomisresponsibleformagnetsandmagneticfields.

Lesson

1. Whenthekidscomein,Ipourmyselfabigbowlofcereal,addthemilkandstartmunchingawaywithoutsayingawordtothem.Thisusuallygetsacoupleofthestudentstopipeupaboutmagnetismfromthosewhoremembertodotheirhomework.Starttoday’slabwithaquickrecapdiscussionoftheirdiscoverieswiththecerealexperiment.

2. Kidswillhavearticlestoshare.Take10‐12minutesandlet4‐7kidssharetheirstorieswiththeclass.Askidsdescribehowelectricityisusedtoimproveoursociety,makearunninglistsoeveryonecanviewit.

3. Announcetothekidsthattodaytheyaregoingtobreakthingsduringthelab.Thisshouldgetyouafewcheers,afterwhichyoucanstartthelab.

LabTime



2. Takeyourmagnetsandfindthepolesthatrepel.Withapencil,writeNontheendofthemagnetsthatrepeleachother.Onthetwooppositepoles,writeS.PutoneNandoneSendtogethertochecktobesuretheyareattractedtoeachother.Themagnetsmighthavetheirpolesonthetopsurfaceandbottomsurface,oroneateachend.Howistherectangularmagnetdifferentfromthecircular?

3. Grabahammerandbreakoneoftherectangularmagnets.Ifitsmashesintomorethantwopieces,that’sOK,butyouwantatleastacoupleofbigpieces.(Thisisfuntowatchthekids,asmostofthetimethehammerwillattractthemagnetandsticktoitastheytrytosmackit.Soon,thekidswillfigureoutthatthemagnetdoesn’thavetolieflatonthegroundinordertobreakit.)

4. Trytopiecethemagnetbacktogether.Whathappens?5. Bringtheunbrokenmagnetclosetooneofthepieces.Doesitattractorrepel?Whichpoledoesthatmake

thisnewend?Usingthemagnetyoudidn’tbreak,labelthenewpolesofthenewsmallermagnetswithNandSasappropriate.Whatdidyoufind?

Exercises

1. Howmanypolesdoesamagnethave?(Two.)2. Whathappenswhenyoutrytoseparatethepoles?(Themagnetsproutstwolikepolesatthebreakpoint,

makingtwomagnetseachwithtwoopposingpoles.)3. Wereyouabletoputthemagnetbacktogetherintoonesinglemagnet?(No.Theyarepermanently

separatemagnetswiththeirownpoles.)4. Wherearethepolesonthecircularmagnet?Isthisdifferentfromyourrectangularmagnet?(Thisisgoing

tovarydependingonyourmagnet,butmostcircularmagnetshaveatop‐bottompolelocationwhilesomerectangularmagnetshavethepolesateitherend.)



Lesson#2:BreakingMagnetsStudentWorksheet

Name______________________________________________________________________

Overview:Today,yougettobreakthingsandcallitscienceasyouinvestigateoneofthefundamentalconceptsinmagnetismthatmagneticpolesareinseparable.

WhattoLearn:Allmagnetshavetwopoles.Magnetsarecalleddipolar,whichmeanstheyhavetwopoles.Thetwopolesofamagnetarecallednorthandsouthpoles.Oppositepoleswillattractoneanother.Likepoleswillrepeloneanother.

Materials

2rectangularmagnets 1circularmagnet Hammertobreakamagnet

LabTime

1. Taketwomagnetsandfindthepolesthatrepel.Withapencil,writeNontheendofthemagnetsthatrepeleachother.Onthetwooppositepoles,writeS.PutoneNandoneSendtogethertochecktobesuretheyareattractedtoeachother.Themagnetsmighthavetheirpolesonthetopsurfaceandbottomsurface,oroneateachend.Howistherectangularmagnetdifferentfromthecircular?________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

2. Grabahammerandbreakoneoftherectangularmagnets.Ifitsmashesintomorethantwopieces,that’sOK,butyouwantatleastacoupleofbigpieces.

3. Trytopiecethemagnetbacktogether.Whathappens?________________________________________________________________________________________________________________________________________________________________________________________________________________________________________


4. Bringtheunbrokenmagnetclosetooneofthepieces.Doesitattractorrepel?Whichpoledoesthatmakethisnewend?Usingthemagnetyoudidn’tbreak,labelthenewpolesofthenewsmallermagnetswithNandSasappropriate.Whatdidyoufind?________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

5. Drawyourbrokenmagnetbothbeforeandafteryousmashedit,labelingallthepoleswithNorS.

ExercisesAnswerthequestionsbelow:1. Howmanypolesdoesamagnethave?

2. Whathappenswhenyoutrytoseparatethepoles?

3. Wereyouabletoputthemagnetbacktogetherintoonesinglemagnet?

4. Wherearethepolesonthecircularmagnet?Isthisdifferentfromyourrectangularmagnet?


Lesson#3:WhichWayisNorth?TeacherSection

Overview:Icanstillrememberinsecond‐gradescienceclasswonderingaboutthisidea.AndIstillrememberhowbaffledmyteacherwaswhenIaskedherthisquestion:“Doesn’tthenorthtipofacompassneedlepointtothesouthpole?”Thinkaboutthis–ifyouholdupamagnetbyastring,justliketheneedleofacompass,doesthenorthendofthemagnetlineupwiththenorthorsouthpoleoftheearth?


Objectives:Studentsaregoingtolearnhowcompassesturnwiththeforceofthemagneticfield.Theywillmeasurethefieldfromamagnetbymappingthetwodifferentpolesandhowthelinesofforceconnectthetwo.Amagneticfieldmustcomefromanorthpoleofamagnetandgotoasouthpoleofamagnet(oratomsthathaveturnedtothemagneticfield.)


Magnet Compass String Ruler

LabPreparation

1. Printoutcopiesofthestudentworksheets.2. Watchthevideoforthisexperimenttoprepareforteachingthisclass.3. Precutthestringinto12”pieces,oneperlabgroup.4. ReadovertheBackgroundLessonReadingbeforeteachingthisclass.


Rightunderyourfeet,there’samagnet.Goaheadtakealook.Liftupyourfeetandseewhat’sunderthere.Doyouseeit?It’shuge!Infact,it’sthelargestmagnetontheEarth.Asamatteroffact,itistheEarth!That’sright;theEarthisonehuge,gigantic,monolithicmagnet!We’regoingtouseamagnettosubstitutefortheEarthandplotoutthemagneticfieldlines.

Lesson

1. ThemagneticpolewhichwasattractedtotheEarth’sNorthPolewaslabeledastheBorealor“north‐seekingpole”inthe1200s,whichwaslatershortenedto“NorthPole”.Toaddtotheconfusion,geologistscallthispoletheNorthMagneticPole.

2. Kidsaregoingtomaketheirowncompassesinoneofthenextlessons;howeveryoumightwanttodemohowacompassismagnetizedbyskippingaheadandmakingamodelrightinfrontofthemsotheycanseehowandwhyitworks.

3. Afterthekidsplaywiththeirmagnetsandcompasses,leadthemthroughthestepsforchartingmagneticlines.


4. KidswillusetheircompassestointroducethemtotheideaoftheEarth’smagneticfield.Ifyourememberaboutmagnets,youknowthatoppositeattract.SothenorthtipofthecompasswilllineupwiththeEarth’sSOUTHPole.Socompassesareupside‐down!

LabTime


2. Tieastringaroundyourmagnet.3. Bringitclosetothecompass.4. Whichendisthenorthendofyourmagnet?Labelitwithapencilrightonthemagnet.5. Flipthemagnetaroundbytwistingthestringsothatthecompassflipstotheoppositepole.Labelthe

oppositesiteofthemagnetwiththeappropriateletter(NorS).6. Bringasecondmagnetclosetothefirstone.Whathappenswhenyoubringtwooppositepolestogether?

Whatifthepolesarethesame?

Nowuntieorcutthestringforthenextpartofyourlab.

7. Layapieceofpaperonyourdesk.8. Placethemagnetinthemiddleofthepaperandtracetheoutline.9. Draw12dots(justlikeonaclock)allthewayaroundthemagnet.Thesearethelocationswhereyouwill

placeyourcompass,somakesurethattheyarecloseenoughtothemagnetsothemagnetinfluencesthecompass.

10. Placeyourcompassononeofthedotsandlookatthedirectionthearrowispointing.Removethecompassanddrawthatexactarrowdirectionrightoveryourdot.Dothisforall12dots.

11. Drawanotherringofdotsaninchortwooutfromthefirstringandrepeatstep9.12. Dothisforathirdandfourthringofdots.

Exercises

1. Howarethelinesofforcedifferentforthetwomagnets?(Sincethisisgoingtodependonthekindofmagnetsyouuse,refertothedatacollected.)

2. Howfarout(ininchesmeasuredfromthemagnet)doesthemagnetaffectthecompass?(Sincethisisgoingtodependonthekindofmagnetsyouuse,refertothedatacollected.)

3. Whatmakesthecompassmovearound?(Themagneticlinesofforcethatareinvisibletoyoureye.)4. Doyouthinkthecompass’snorth‐southindicatorisflipped,ortheEarth’sNorthPoleiswheretheSouth

Poleshouldbe?Howdoyouknow?(It’sanarbitrarydenotation,buttheEarth’sNorthPoleisdeemedtobenorth.)

ClosureBeforemovingon,askyourstudentsiftheyhaveanyrecommendationsorunansweredquestionsthattheycanworkoutontheirown.Brainstormingextensionideasisagreatwaytoaddmoresciencestudiestoyour

classtime.


Lesson#3:WhichWayisNorth?StudentWorksheet

Name______________________________________________________________________

Overview:You’regoingtouseacompasstofigureoutthemagneticlinesofforcefromamagnetbymappingthetwodifferentpolesandhowthelinesofforceconnectthetwo.Amagneticfieldmustcomefromanorthpoleofamagnetandgotoasouthpoleofamagnet(oratomsthathaveturnedtothemagneticfield.)

WhattoLearn:Compassesareinfluencedbymagneticlinesofforce.Theselinesarenotnecessarilystraight.Whentheybend,thecompassneedlemoves.TheEarthhasahugemagneticfield.TheEarthhasaweakmagneticforce.ThemagneticfieldcomesfromthemovingelectronsinthecurrentsoftheEarth’smoltencore.TheEarthhasanorthandasouthmagneticpolewhichisdifferentfromthegeographicNorthandSouthPole.

Materials

Rectangularmagnet Circularmagnet Compass String Ruler

LabTime

1. Tieastringaroundyourmagnet.2. Bringitclosetothecompass.3. Whichendisthenorthendofyourmagnet?Labelitwithapencilrightonthemagnet.4. Flipthemagnetaroundbytwistingthestringsothatthecompassflipstotheoppositepole.Labelthe

oppositesiteofthemagnetwiththeappropriateletter(NorS).5. Bringasecondmagnetclosetothefirstone.Whathappenswhenyoubringtwooppositepolestogether?

Whatifthepolesarethesame?Writedownyourobservationshere:________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Nowuntieorcutthestringforthenextpartofyourlab.

6. Layapieceofpaperonyourdesk.


7. Placethemagnetinthemiddleofthepaperandtracetheoutline.8. Draw12dots(justlikeonaclock)allthewayaroundthemagnet.Thesearethelocationswhereyouwill

placeyourcompass,somakesurethattheyarecloseenoughtothemagnetsothemagnetinfluencesthecompass.

9. Placeyourcompassononeofthedotsandlookatthedirectionthearrowispointing.Removethecompassanddrawthatexactarrowdirectionrightoveryourdot.Dothisforalltwelvedots.

10. Drawanotherringofdotsaninchortwooutfromthefirstringandrepeatstep9.11. Dothisforathirdringofdots.12. Repeatsteps6‐10withacircularmagnetonanewsheetofpaper.

Exercises

Answerthequestionsbelow:

1. Howarethelinesofforcedifferentforthetwomagnets?

2. Howfarout(ininchesmeasuredfromthemagnet)doesthemagnetaffectthecompass?

3. Whatmakesthecompassmovearound?

4. Doyouthinkthecompass’snorth‐southindicatorisflipped,ortheEarth’sNorthPolewheretheSouthPoleis?Howdoyouknow?


Lesson#4:FlyingPaperclip

TeacherSection

Overview:Theinverse‐squarelawappliestoquiteafewphenomenainphysics.Whenitcomestoforces,itbasicallymeansthatthecloseranobjectcomestothesourceofaforce,thestrongerthatforcewillbeonthatobject.Thefartherthatsameobjectgetsfromtheforce’ssource,theweakertheeffectoftheforce.


Objectives:Infields,theclosersomethinggetstothesourceofthefield,thestrongertheforceofthefieldgets.Thisiscalledtheinversesquarelaw.Thoseatomsarelinedupinthesamedirection,sothatobjectwillhaveamagneticforce.


Fourdifferentmagnets Paperclip String Ruler Tape

LabPreparation

1. Printoutcopiesofthestudentworksheets.2. Watchthevideoforthisexperimenttoprepareforteachingthisclass.3. Precutthestringinto12”longpieces.4. I’llpre‐ripthetapeandstickitpart‐wayhangingofftheedgeofmydeskthatkidscaneasilyreachsothey

canhelpthemselveswhentheyneedit.Youmightopttogiveeachtheirveryowntapedispenser.

Lesson

1. Haveyoueverbeenclosetosomethingthatsmellsbad?Haveyounoticedthatthefartheryougetfromthatsomething,thelessitsmells,andthecloseryouget,themoreitsmells?Well,forcessortofworkinthesameway.

2. Forcesbehaveaccordingtoafancylawcalledtheinverse‐squarelaw.Tobetechnical,aninverse‐squarelawisanyphysicallawstatingthatsomephysicalquantityorstrengthisinverselyproportionaltothesquareofthedistancefromthesourceofthatphysicalquantity.

3. Theinverse‐squarelawmeansthatthecloseranobjectcomestothesourceofaforce,thestrongerthatforcewillbeonthatobject.Mathematically,wecansaythatdoublingthedistancebetweentheobjectandthesourceoftheforcemakestheforce1/4thasstrong.Triplingthedistancemakestheforce1/9thasstrong.

4. Optional:Youcandemonstratetheinversesquarelawifyouhavealightweightspringscale.Attachthescaledirectlytothemagnet.Placearulerdownonthetablewiththezeromarklinedupwithendofthepaperclip.Takeforcemeasurementsfromthescaleeveryhalfinchandwritethesedownontheboard.Thisisanexcellenttimetoshowthestudentshowtographdatabyplacingtheforcereadingsonthevertical


scale(y‐axis)andthedistancemeasurementsonthehorizontalscale(x‐axis).You’llseeagraphicalrepresentationoftheinversesquarelaw.

LabTime


2. Tiethestringtooneofthemagnets.3. Tapetheendofthestringtothetable.4. Bringyourmagnetclosetothepaperclipsothepaperclipfliesuptoit.5. Usingaruler,measurehowfarawayyourmagnetiswhenthepaperclipfallsbacktothetable.Whichpartof

yourmagnetisitmostattractedto?Whichpartofthemagnetisthestrongest?That’sthesideofthemagnetwewanttousewhenyourecordyourdata.

6. Repeatsteps3and4withallofyourdifferentmagnets.7. Completethedatatable.(Don’tforgetyourunitsincolumn3!Didyoumeasureininches,feet,centimeters…?)

Exercises

1. Circleone:Thecloseryougettothemagnet,the(strongerweaker)theforceofthemagneticfieldisonthepaperclip.

2. Whydoesitmatterwhichwayyouorientthemagnetinthisexperiment?(Themagneticforceisstrongestatthemagneticpoles.)

3. Whichmagnethasthestrongestmagneticfield?(Refertoyourdata.)4. Isthenorthorsouthpolestrongeronamagnet?(Neither–theyareidenticalinforce.)

ClosureBeforemovingon,askyourstudentsiftheyhaveanyrecommendationsorunansweredquestionsthattheycanworkoutontheirown.Brainstormingextensionideasisagreatwaytoaddmoresciencestudiestoyour

classtime.


Lesson#4:FlyingPaperclipStudentWorksheet

Name______________________________________________________________________

Overview:Infields,theclosersomethinggetstothesourceofthefield,thestrongertheforceofthefieldgets.Thisiscalledtheinversesquarelaw.Thoseatomsarelinedupinthesamedirection,thatobjectwillhaveamagneticforce.

WhattoLearn:Theinverse‐squarelawappliestoquiteafewphenomenainphysics.Whenitcomestoforces,itbasicallymeansthatthecloseranobjectcomestothesourceofaforce,thestrongerthatforcewillbeonthatobject.Thefartherthatsameobjectgetsfromtheforce’ssource,theweakertheeffectoftheforce.

Materials

Fourdifferentmagnets Paperclip String Ruler Tape

LabTime

1. Tiethestringtooneofthemagnets.2. Tapetheendofthestringtothetable.3. Bringyourmagnetclosetothepaperclipsothepaperclipfliesuptoit.4. Usingaruler,measurehowfarawayyourmagnetiswhenthepaperclipfallsbacktothetable.Whichpart

ofyourmagnetisitmostattractedto?Whichpartofthemagnetisthestrongest?That’sthesideofthemagnetwewanttousewhenyourecordyourdata.

5. Repeatsteps3and4withallofyourdifferentmagnets.6. Completethedatatable.(Don’tforgetyourunitsincolumn3!Didyoumeasureininches,feet,

centimeters…?)


FlyingPaperClipDataTable

Type/ShapeofMagnet Whichpartisthestrongest? Howfarbeforethepaperclipfalls?

Exercises:Answerthequestionsbelow:

1. Circleone:Thecloseryougettothemagnet,the(stronger|weaker)theforceofthemagneticfieldisonthepaperclip.

2. Whydoesitmatterwhichwayyouorientthemagnetinthisexperiment?

3. Whichmagnethasthestrongestmagneticfield?

4. Isthenorthorsouthpolestrongeronamagnet?

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Lesson

1. Holdupacoupleofmagnetsandaskthekidswhytheywillstayput,evenifyouletgoofthestackexceptforthetopmagnet.Noticethatifthenorthpoleofthebottommagnetisup,thenthesouthpoleofthemagnetstackedaboveitwillbedown.

2. Thestackholdstogetherbecauseoppositesattract(north‐south).3. Nowplacethemagnetstackonthetabletodemonstrate.4. Noticewhenyoupullthetopmagnettotheside,thebottomsouthfaceisrepelledintotheairabovethe

northfaceofthefixedmagnet.Sowhat’sgoingon?Askthemfortheirideas.Thenstartupthelab.

LabTime


2. Stacktwomagnetsontopofeachothersotheyareallorientedinthecorrectdirection.3. Slideoneoffthetopandfindamagicspotwhereithoversinmid‐air.Thistakespatience,soworkslowly.4. Givethetopofthefloatingmagnetagentletap.5. Youshouldseethemagnetvibrateintheair.Usingtheclockinyourclassroom,timehowlongitvibrates.6. Nowrestackthetwomagnetsandaddathird.Slidethetoponeoffandmoveittotheside,awayfrom

whereyou’reworking,butbesurenottoflipit.7. Slidethesecondmagnetoffandagainfindamagicspotwhereithoversinmid‐air.8. Slowlymovethemagnetthat’sofftothesidetowardyou.Youwanttoadditveryslowlytotheotherside

ofthenon‐movingmagnet.9. Giveoneofthefloatingmagnetsagentletap.Youshouldnotonlyseethemagnetvibrateintheair,butthe

secondmagnetmovingaswell.10. Doyounoticehowsometimesonefloatingmagnetmovesmore,andthenslowsdownastheotherfloating

magnetstartstoincreaseitsmovement?Whatdoyouthinkisgoingon?11. Youcanadjustyourtwobouncingmagnetstohavenearlythesame“bounce”(frequency)bychangingtheir

distanceapart.Noticethatwhenonemagnetstartsbouncing,themagneticfieldchanges,whichpushesandpullsontheothermagnet.Thetwomagnetsinteractwitheachotherthroughtheirmagneticfields,pushingandpullingeachotherintoresonance.Howfarapartareyourmagnetswhenitworksbest?

12. What’sgoingon?Rememberthatamagnetisn’tstrictlynorthorsouth.Therearefieldlinesthatconnectthetwopoles.Thefieldlinesstartatoneendandswoopdowntotheotherandbackagainlikeinthispicturetotheleft,reversingfromnorthtosouthasitdoesso.Thisiswhythesouthfaceisrepelled–becauseit’sactuallythemagneticfieldsthataredoingtherepelling.

13. Workingwithanotherlabgroupthat’sready,whathappensifyoutryfloatingthreeorfourmagnets?14. Optional:Youcanbringoverasheetofmetal.Whathappenswhenthismetalsheetplacedabovethe

bouncingmagnetexperiment?(Note:thethickerthepieceofmetal,thebetteritworks.)

Exercises

1. Whydoesthemagnetfloat?(Likepolesrepeleachother,right?Butthere’sonemorestepinunderstandingthisexperiment–it’snotjustthepoleswearedealingwith,it’sthemagneticfields.Rememberthatamagnethasfieldlinesthatconnectthetwopoles,andit’sthemagneticfieldsthataredoingtherepelling.)


2. Afteryoutapthefloatingmagnet,doesitvibrateforashortorlongtime?Why?(Loooongbecausethere’slittlefrictionintheexperiment.)

3. Whydowestackthemagnetsfirstbeforetryingtolevitatethem?(Initiallyyourmagnetsstackupbecausetheyarenorthonthetopsurfaceandsouthbetheentirebottomsurface.Thepolesareallfacingthesamewaysothelikepoleswillrepelandlevitatethemagnet.)

4. Howmanymagnetscanyougettointeractwhilefloating?(Mypersonalrecordissix.)5. Whenyoufloattwomagnetsabovethemainmagnet,howdothefloatingmagnetsinteractwitheachother?

Whydotheydothat?(Whenonemagnetstartsbouncing,themagneticfieldchanges,whichpushesandpullsontheothermagnet.Thetwomagnetsinteractwitheachotherthroughtheirmagneticfields,pushingandpullingeachotherintoresonance.There’sanenergytransfergoingonbetweenthemagnets.)

Closure:Beforemovingon,askyourstudentsiftheyhaveanyrecommendationsorunansweredquestionsthattheycanworkoutontheirown.Brainstormingextensionideasisagreatwaytoaddmoresciencestudiestoyourclasstime.


Lesson#5:BouncingMagnetsStudentWorksheet

Name______________________________________________________________________

Overview:Wanttoseeareallyneatwaytogetmagneticfieldstointeractwitheachother?Whilelevitatingobjectsishard,bouncingthemininvisiblemagneticfieldsiseasy.Inthisexperiment,studentswilltaketwo,three,orevenfourmagnetsandhavethemperformtheirantics.

WhattoLearn:We’reputtingtogethertheideasoftheinversesquarelawandmagneticfieldsbyhavingyouplaywiththeinvisiblemagneticlinesofforce.

Materials

3identicalmagnets Optional:thickpieceofaluminum

LabTime

1. Stacktwomagnetsontopofeachothersotheyareallorientedinthecorrectdirection.2. Slideoneoffthetopandfindamagicspotwhereithoversinmid‐air.Thistakespatience,soworkslowly.3. Givethetopofthefloatingmagnetagentletap.4. Youshouldseethemagnetvibrateintheair.5. Usingtheclockinyourclassroom,timehowlongitvibrates:_________________________________(unitoftime?)6. Nowrestackthetwomagnetsandaddathird.Slidethetoponeoffandmoveittotheside,awayfrom

whereyou’reworking,butbesurenottoflipit.7. Slidethesecondmagnetoffandagainfindamagicspotwhereithoversinmid‐air.8. Slowlymovethemagnetthat’sofftothesidetowardyou.Youwanttoadditveryslowlytotheotherside

ofthenon‐movingmagnet.9. Giveoneofthefloatingmagnetsagentletap.Youshouldnotonlyseethemagnetvibrateintheair,butthe

secondmagnetmovingaswell.10. Doyounoticehowsometimesonefloatingmagnetmovesmore,andthenslowsdownastheotherfloating

magnetstartstoincreaseitsmovement?Whatdoyouthinkisgoingon?Writeithere:___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________


11. Youcanadjustyourtwobouncingmagnetstohavenearlythesame”bounce”(frequency)bychangingtheirdistanceapart.Noticethatwhenonemagnetstartsbouncing,themagneticfieldchanges,whichpushesandpullsontheothermagnet.Thetwomagnetsinteractwitheachotherthroughtheirmagneticfields,pushingandpullingeachotherintoresonance.Howfarapartareyourmagnetswhenitworksbest?___________________________________________________________________________________________________(units?)

12. Workingwithanotherlabgroupthat’sready,whathappensifyoutryfloatingthreeorfourmagnets?13. Yourteachermaybringoverasheetofmetal.Whathappenswhentheyplaceitaboveyourexperiment?

Writeithere:___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

ExercisesAnswerthequestionsbelow:1. Whydoesthemagnetfloat?

2. Afteryoutapthefloatingmagnet,doesitvibrateforashortorlongtime?Why?

3. Whydowestackthemagnetsfirstbeforetryingtolevitatethem?

4. Howmanymagnetscanyougettointeractwhilefloating?

5. Whenyoufloattwomagnetsabovethemainmagnet,howdothefloatingmagnetsinteractwitheachother?Whydotheydothat?


Lesson#6:MagneticFieldsTeacherSection

Overview:StudentswillmaketheirowncompassestodetecttheEarth’smagneticfield.ThisisthesecondpartofthelabstartedinExperiment3:WhichWayisNorth?Theoptionalactivityattheendwillroundouttheexperimentbyshowingthekidshowwecan’tdetectthestrengthofthemagneticfieldeasily.


Objectives:Kidstodaywilllearnhowtobuildasimplecompassanduseittodetectmagneticeffects,includingEarth'smagneticfield.


Needleorpin Strongestmagnet Smallpieceoffoam(likeapackingpeanut) Disposablecup Water Compass Optional:filmcanistersorsmallplasticcontainers Optional:6roundmagnetsthatfitinsideyourcontainerwhenstacked Optional:Tissues

LabPreparation

1. Printoutcopiesofthestudentworksheets.2. Watchthethreevideostohelpyouprepareforthisexperimentandforteachingclasswithconfidence.3. ReadovertheBackgroundLessonReadingbeforeteachingthisclass.4. Stickthepininthefoamandputthepinnexttothemagnetsoitsticks.Placethewholethinginthecupso

thekidscaneasilyfindeverythingtheyneedallinoneplace.Ifyouhaveastrongmagnet,don’tplacethecompassnexttoitinthecuporyoumightruinthecompass.

5. Ifyouhaveglobe(inflatableortheold‐fashionedkindonanaxis),bringitouttopointtoasyoudiscussthelesson.YoucanputasmallpieceoftapeonthetwogeographicpolesoftheEarthsoit’llbeeasytopointthemoutlater(seebelowforexactlocation).


RememberhowwelearnedthattheEarthisagiganticmagnet?WedidanexperimentwherewemappedthemagneticfieldlinesbackinExperiment3.Doyoualsorecallhowmagnetismiscausedbyelectronspin?Sothequestionis…wheredoestheEarth’smagneticfieldcomefrom?

Atthispoint,folksarestilltryingtofigurethatout.ThemostwidelyacceptedtheoryisthatthemagneticfieldcomesfromtheEarth’score.ThecoreoftheEarthissolid,butaroundthatcoreisaliquid.Theliquidisbasicallymolteniron,nickelandafewotherelements.ItistheflowingoftheelectronsinthisliquidmetalthatprobablycausestheEarth’smagneticfield.


So,yes,theEarthisamagnet,butnotaverystrongone.Youprobablycouldn’tevenstickittoasun‐sizedrefrigerator.TheEarthhasamagneticpull100timesweakerthenthemagnetsonyourfridge.TheEarth,bytheway,isnottheonlygiantmagnetinthesolarsystem.TheSun,Jupiter,Saturn,Uranus,MercuryandNeptunearealsomagnets.

“Oh,yeah.NowIremember.That’sthedealwiththeNorthandSouthPolesright?”

Well,yesandno.Toconfusethingsabit,therearetwosetsofNorthandSouthPoles.TherearethegeographicNorthandSouthPolesandthemagneticNorthandSouthPoles.(Tobecompletelyhonest,thereareEIGHTmagneticpolesontheEarth,butwe’lljustfocusonthetwostrongestonefornowtocutdownontheconfusion.)

ThegeographicpolesarelocatedattheaxisoftheEarth.TheaxisiswheretheEarthturnsdayafterday.Themagneticpolesareclosetothegeographicpoles,buttheyareoffbyquiteabit.(TheSouthPoleisn’teveninAntarctica–it’sintheocean.)Infact,thenorthandsouthmagneticpolesoftheEarthmovefromyeartoyearandhavecompletelyflippedacoupleoftimes.IfyouweretoconnecttheEarth’smostprominentnorthandsouthpoles,theywouldn’tcutthroughtheplanet,sincetheyarebothonthesameside.

Inthisexperiment,we’regoingtomakeourowncompassbymagnetizinganeedlesothatitactslikeatinymagnet.Byfloatingtheneedleinacup,itwillbeabletoeasilyturntoalignitselfwiththemagneticfieldoftheEarth.

TheNorthMagneticPolein2001wasnearEllesmereIslandinnorthernCanadaat81.3°N110.8°W.Asof2012,thepoleisprojectedtohavemovedbeyondtheCanadianArcticterritorialclaimto85.9°N147.0°W.ThispoleismovingtowardRussiaatarateof34‐37milesperyear.

TheSouthMagneticPoleisconstantlyshiftingduetochangesintheEarth'smagneticfield.Asof2005itwascalculatedtolieat64°31′48″S137°51′36″EjustoffthecoastofAdelieLand,FrenchAntarctica.ThatpointliesoutsidetheAntarcticCircle.Duetopolardrift,thepoleismovingnorthwestbyabout10to15kilometersperyear.

Lesson

1. Ifyouhaveaccesstoironfilings,sliptheminaclearplasticzipper‐typebaggieorontopofathinsheetofplastic.Thisisagreatwaytodemonstratemagneticfieldlineswithoutmakingyourmagnetpermanentlycoatedwithironhairballs.Watchthefirstvideofortipsonhowtodothisdemonstration.

2. Ifyou’veeverplayedwithacompass,youknowthatnomatterwhichwayyouturnit,theneedlealwayspointsnorth.Whyisthat?

3. It’sbecauseweliveonagiantmagnetcalledtheEarth.TheneedlefollowsthemagneticpoleoftheEarth.4. Announcetoyouryoungchargesthatyouaregoingtomakeacompassandstartthemontheirscientific

expedition.Watchthesecondvideotoseehowtomakeacompassbeforeclassstarts.

LabTime


2. Fillacupwithwater.Youdon’tneedmuch–justenoughtofloatapieceoffoamin.3. Takeyourneedleandwipeitseveraltimesonallsideswiththemagnet.Makesureyou’reonlycontacting

thepinandstrokingitinonedirection.You’regettingtheelectronstoallspininthesamedirection,likeliningupallthosetinymagnetsinthevirtualshoeboxwetalkedaboutbefore.

4. Pierceapieceoffoamwiththepin.Stickitrightthroughthemiddle.


5. Placetheneedlecarefullyinthewater.Ifyousplasharound,you’regoingtohavetowaitawhileforthesystemtosettledownbeforeyoutakeareading.

6. Lookatyourhomemadecompass.Whichwayistheneedlepointing?7. Compareitwithyourready‐madestore‐boughtcompass.Aretheybothtellingyouthesamething?(Ifnot,

you’llneedtoremovethepinfromthefoamandrepeatstep3again.)8. Filloutthedatatable.

Optional:Thisisanadditionaldemonstrationthatillustratesthestrengthofthemagneticfield.Iusuallymakeacoupleoftheseandpainttheoutsidessothekidscan’tseewhichonehasmoremagnetsinit.(Bonuspointsaregiventothekidswhofigureoutthatyoucan’ttellwhichiswhich.)

1. Stacksixmagnetsupinatallstack.2. Takethreeoffthetopandplopthemintooneofyourcontainers.3. Addapieceoftissuesothemagnetsdon’tslidearound,andputthetopon.4. Placetherestofthemagnetsinthesecondcontainer,addingtissuebeforeyoucapit.5. Whenyouplacethebottomsofthecontainerstogether,youshouldfeelarepulsiveforce.Iftheystick

instead,openuponeofthecontainersandflipthemagnetsaround.6. Northandnorthpolesrepeleachother.Youshouldfeelthiswhenyoutrytopushthebottomsofthe

containerstogether.7. Nowopenupthecontainersandputfiveinoneandoneintheother,replacingthetissuebeforeyoucap

eachcontainer.8. Placethecontainersonthetablesoyoucan’ttellwhichiswhichbyweight.Nowbringthebottomsclose

together.Whichonehasmoremagnetsinit?9. Youwon’tbeabletotell!Eventhoughonehasfivetimesthenumberofmagnetsinside,itdoesn’texertfive

timestheforce.Youcandemonstratethisbyattachingoneofthecanisterstoalightweightspring‐scaleorfish‐scalebeforebringingitclosertotheothermagneticcanister.

Exercises

1. Whycan’tyousimplyrubtheneedlebackandforthwiththemagnet?Whydoyouhavetostrokeitinonedirection?(Whenyourubtheneedlewiththemagnet,youlineuptheironatomsallinthesamedirection.Ifyourubinbothdirections,thentheatomsgetlinedupeverywhichway.)

2. Whatotherobjects/materialscanyouusetomakeacompass?(Anythingwithiron,nickel,orcobaltinit,andputitinalow‐frictionenvironmentliketheendofapinorfloatinginwater.)

3. Howdoyouknowthattheneedleismagnetized?(Whenit’salignedwiththecompassneedle.)4. Whydidwefloattheneedleinwater?(Tokeepthefrictionlow,sotheneedleisfreetomoveandalignwith

theEarth’smagneticfield.)



Lesson#6:MagneticFieldsStudentWorksheet

Name______________________________________________________________________

Overview:TodayyougettomakeyourowncompasstodetecttheEarth’smagneticfield.

WhattoLearn:Notonlyhowtobuildasimplecompassanduseittodetectmagneticeffects,includingEarth'smagneticfield,butalsohownottobuildacompass.

Materials

Needleorpin Strongestmagnet Smallpieceoffoam(likeapackingpeanut) Disposablecup Water Compass

LabTime

1. Reviewtheinstructionsontheirworksheetsandthenbreakintoyourlabgroups.Getyourmaterialsfromyourteacher.

2. Fillacupwithwater.Youdon’tneedmuch–justenoughtofloatapieceoffoamin.3. Takeyourneedleandwipeitseveraltimesonallsideswiththemagnet.Makesureyou’reonlycontacting

thepinandstrokingitinonedirection.You’regettingtheelectronstoallspininthesamedirection,likeliningupallthosetinymagnetsinthevirtualshoeboxwetalkedaboutbefore.

4. Pierceapieceoffoamwiththepin.Stickitrightthroughthemiddle.5. Placetheneedlecarefullyinthewater.Ifyousplasharound,you’regoingtohavetowaitawhileforthe

systemtosettledownbeforeyoutakeareading.6. Lookatyourhomemadecompass.Whichwayistheneedlepointing?7. Compareitwithyourready‐madestore‐boughtcompass.Aretheybothtellingyouthesamething?(Ifnot,

you’llneedtoremovethepinfromthefoamandrepeatstep3again.)8. Filloutthedatatable.


MagneticFieldsDataTable

MagnetizingtheNeedle Doesitalignwiththecompass?Wipedinonedirectionfor20strokes

Wipedinonedirectionfor50strokes

Wipedinotherdirectionfor50strokes

Rubbedbackandforthinbothdirectionsfor20strokes

Layingitonthemagnetforoneminute(nowipingorstroking)

Exercises:Answerthequestionsbelow:

1. Whycan’tyousimplyrubtheneedlebackandforthwiththemagnet?Whydoyouhavetostrokeitinonedirection?

2. Whatotherobjects/materialscanyouusetomakeacompass?

3. Howdoyouknowthattheneedleismagnetized?

4. Whydidwefloattheneedleinwater?


Lesson#7:MagneticSensorsTeacherSection

OverviewWouldn’titbecooltohaveanalarmsoundeachtimesomeoneopenedyourdoor,lunchbox,orsecretdrawer?It’seasywhenyouuseareedswitchinyourcircuit!Ifyou’vebuildtheburglaralarmfromtheunitonElectricity,thisisagreatadditiontoyourstashoftop‐secretspyalarms.

SuggestedTime30‐45minutes

ObjectivesKidswilllearnhowtowireupandutilizeamagnetically‐operatedswitch.


Reedswitch Magnet LED AAcase 2alligatorwires 2AAbatteries

LabPreparation

1. Printoutcopiesofthestudentworksheets.2. Watchthevideoforthisexperimenttoprepareforteachingthisclass.3. ReadovertheBackgroundLessonReadingbeforeteachingthisclass.


Areedswitchisaswitchthatturnsonandoff,dependingonifamagnetiscloseornot.Areedswitchhastwostripsofmetalthatareclosebutnottouchinginside.Whenthemagnetisclose,thetwostripsofmetalmoveclosertogetheruntiltheytouch,whichallowsthecurrenttoflowandmakestheLEDlightup.

Lesson

Ifyouhaven’talreadygonethroughbasiccircuitswithyourstudents,herearethebasicsteps.WecovertheseintheunitonElectricity.

1. UsethematerialstowireupasimplecircuitandgettheLEDtolightup:a. Insertyourbatteriesintothecase.Flatside(minus)goestothespring.b. Attachonealligatorcliptoeachofthemetaltipsofthewiresfromthebatterycase.Makesure

you’vegotagoodmetal‐to‐metalconnection.Youshouldnowhavetwoalligatorclipsattachedtothebatterypack.

c. Attachtheendofthealligatorclipsthat’sconnectedtotheblackwire(negative)fromthebatterycasetotheflatsideoftheLED.Itdoesn’tmatterwhatcolorthealligatorclipwireis.

d. Attachtheotheralligatorclipthat’sconnectedtotheredwire(positive)fromthebatterycasetothelongerLEDwire.Again,itdoesn’tmatterwhatcolorthealligatorclipwireis.


e. YourLEDshouldlightup!2. Troubleshootingacircuitthatdoesn’twork:

a. Batteriesinsertedintothecasethewrongway?(Flatsideofthebatteryshouldgotothemetalspringinsidethecase.)

b. LEDisinthecircuitthewrongway?Remember,LEDsarepickyaboutplusandminus,meaningthatitmatterswhichwaytheyareinthecircuit.IfyouchooseabipolarLED,thenyoudon’thavetoworryaboutthisone,sincetherearetwoLEDs,oneineachdirection,inoneLEDpackagewhichwillilluminatenomatterwhichwayyouhaveitinyourcircuit.LEDsarepolarized.

c. Isthereametal‐to‐metalconnection?You’renotgrabbingholdoftheplasticinsulation,areyou?Notevenatinybit?Sometimeskidshavetheedgeofthealligatorclipleadproppedupontheedgeoftheplasticinsulation,whichwillmakeyourconnectionnotwork.

d. Onceinawhile,you’llgetabadalligatorwire.There’saneasytocheckthis:RemoveyouralligatorclipleadsfromthecircuitandtoucheachofthemetaltipsfromthebatterypackwirestotheLEDwires.IftheLEDlightsup,swapoutyouralligatorclipleadwiresfornewonesandthatshouldfixit.

3. Beforelettingthestudentslooseinthelab,makeademonstrationcircuitanddothefollowingthingswrong(andaskthemtohelpyoucorrecttheproblem):

a. Forgettoputinthebatteries.b. Putbatteriesinbackward.c. Connectonlyonewire.d. ConnectthealligatorclipontotheplasticinsulationinsteadoftheLED.e. ForgettoputtheLEDin(Onlydothisforamoment,oryou’llblowupyourbatteries!There’s

nothingforthebatteriestopower,theelectricitygoesrightbackintothebatteries.Thisisnothowyourechargebatteries,bytheway.Youmustputsomethinginthecircuitforyourelectronstodo.).

f. PuttheLEDinbackward.4. Iliketoaskthekidswhofigurethisoutquicklytostandupandwalkaroundandhelptheoneswhocan’tseem

tofigureitout.Thismakesagreatteamworkexerciseforthestudentsandlesshasslefortheteacher.

LabTime


2. AskthekidstolightuptheirLED.Ifyouhaven’tdonethisbefore,refertothelessonabovesoyoucanwalkthemthroughit.

OnceyouhaveyourLEDilluminated,thenyoucanmoveontoinstallingyourreedswitchinyourcircuit.Ifyourreedswitchisburiedinsidepackaging,you’llneedtodigitoutgently.Whenyou’vegottheglasstube,thenyou’rereadyforthenextstep:

3. LightupyourLEDinasimplecircuit.Don’tputinthereedswitchyet–wewanttobesureeverythingworksbeforeintroducinganewelectronicelement.

4. RemoveoneofthealligatorclipsfromanLEDwireandreplaceitwithathirdalligatorcliplead.5. Attacheachoneofthetwofreeendsofalligatorwirestoeitherendofthereedswitch.Youshouldnow

haveacompletecircuitthatlooksalotlikeacirclewhenyoustretchitout.6. Bringyourmagnetclosetotheswitch.WheredoyouhavetopositionyourmagnetsoyourLEDlightsup?7. Drawapictureofhowyoucanusethiscircuitinadoorordrawer:


Exercises

1. Wheredoesthemagnetneedtobelocatedinorderforyourcircuittowork?(Youneedtohavetheswitchlinedupsothatthemagnetishoveringoverthetopofoneofthestrips.)

2. Howdoestheswitchwork?Drawapictureandlabelthepartsthatmakeitworkinthecircuit.3. Cantheswitchbeactivatedthroughthesideofadrawer,sothattheswitchisintheinsideandthemagnet

isontheoutside?(Yes,magneticforcescangothroughmaterialslikepaper,plasticandwoodaslongastheyarethinenoughforthemagneticfieldtopenetrate.)

4. Whichwaydoesthemagnetactivatetheswitchthebest?Howarethepolesorientedrelativetotheswitch?(Onepolewillbepointingtothetopofoneofthemetalstrips.)



Lesson#7:MagneticSensorsStudentWorksheet

Name______________________________________________________________________

Overview:Wouldn’titbecooltohaveanalarmsoundeachtimesomeoneopenedyourdoor,lunchbox,orsecretdrawer?It’seasywhenyouuseareedswitchinyourcircuit!Ifyou’vebuilttheburglaralarmfromtheunitonElectricity,thisisagreatadditiontoyourstashoftop‐secretspyalarms.

WhattoLearn:Today,yougettolearnhowtowireupandutilizeamagnetically‐operatedswitch.

Materials

Reedswitch Magnet LED AAcase 2alligatorwires 2AAbatteries

LabTime

1. First,youneedtolightuptheLED.Ifyouhaven’tdonethisbefore,yourteacherisgoingtowalkyouthroughit.

2. LightupyourLEDinasimplecircuit.Don’tputinthereedswitchyet–wewanttobesureeverythingworksbeforeintroducinganewelectronicelement.

3. RemoveoneofthealligatorclipsfromanLEDwireandreplaceitwithathirdalligatorcliplead.4. Attacheachoneofthetwofreeendsofalligatorwirestoeitherendofthereedswitch.Youshouldnow

haveacompletecircuitthatlooksalotlikeacirclewhenyoustretchitout.5. Bringyourmagnetclosetotheswitch.WheredoyouhavetopositionyourmagnetsoyourLEDlightsup?6. Drawapictureofhowyoucanusethiscircuitinadoorordrawer:


Exercises


1. Wheredoesthemagnetneedtobelocatedinorderforyourcircuittowork?

2. Howdoestheswitchwork?Drawapictureandlabelthepartsthatmakeitworkinthecircuit.

3. Cantheswitchbeactivatedthroughthesideofadrawer,sothattheswitchisintheinsideandthemagnetisontheoutside?

4. Whichwaydoesthemagnetactivatetheswitchthebest?Howarethepolesorientedrelativetotheswitch?


Lesson#8:MagneticBoatsTeacherSection

Overview:Kidsinvestigatemagneticfieldsandmagneticforcesusingstrongercompassesbyfloatingmagnetsinatubofwater.Themagnetsinteractwitheachothertoshowhowtheyrepellikepolesbutstillholdthemselvesinapattern,justlikeatomsandmoleculesdo.


Objectives:Understandlikepolesrepel,oppositesattract,andhowtoasimplecompasscandetectmagneticeffects.


Shallowdishorpietin Water Foamblocks 6‐10smallmagnets Largemagnet Hotgluegun

LabPreparation

1. Printoutcopiesofthestudentworksheets.2. WatchtheVideoforthisexperimenttoprepareforteachingthisclass.3. ReadovertheBackgroundLessonReadingbeforeteachingthisclass.4. Beforeclassstarts,haveyourhotgluegunsoutandheatedup,readytogo.5. Ifthefoamishardtoworkwith,pre‐cutitintoshapeusingasharprazorinto1‐2inchsquares.Youneed

thesamenumberoffoamblocksasyouhavemagnets.


What’samagneticfield?Well,Ican’ttellyou.Tobehonest,nobodycan.Magneticfields,gravitationalfieldsandelectricfieldsareverymysterious,andatthispointtherearestilllotsofquestionsabouteachone.

Afieldisanareaaroundanelectrical,magneticorgravitationalsourcethatwillcreateaforceonanotherelectrical,magneticorgravitationalsourcethatcomeswithinthereachofthefield.(Nowyoucanseewhythere’sstillsomuchmysteryaboutthem!)

Agravitationalfield,forexample,comesfromabodyofsomesort.Thelargerthebody,thegreatertheforcewillbe.Aplanet,forexample,isalargebodywithalargegravitationalforce.Ifanotherbodygetswithinthegravitationalfieldoftheplanet,itwillbeaffectedbytheforce.

Whatcreatestheforce?What’spullingorpushing?Nobodyknows!Wejustknowthatithappens.


Anotherthingaboutforcesisthatthefarthersomethinggetsawayfromthesource,thelessandlesstheforceworksonthatobject.Afancytermforthisistheinversesquarelaw.SomethingquitefarfromtheEarthwillfeelnotugfromtheEarth’sgravitationalpull.Ifitgetscloser,itwillfeelaslighttug.Closerstill,astrongertugwillbefelt.Theclosersomethinggetstothesourceofafield(gravitational,magneticorelectric)thestrongerthepullofthefieldforceis.Ifyou’restandingontopoftheSearsTowerinChicago,youareactuallygoingtoweighlessthanifyou’restandinginthestreet.

Weightdependsonthepullofgravity.ThefartheryouarefromtheEarth,thelessgravitypullsonyouandthelessyouwillweigh!There’saninstantdietplanforyou!

Whenyoubuildthelittleboats,rememberthatyoukeptallthepolesthesame(allnorthpointedup,forexample).Thefloatingmagnetsrepeleachotherbecausetheyhavethesamepoleorientedup.

Butnoticethatwhenyoubringthelargermagnetclose,theyareallattractedtoitandalsomakegeometricpatterns!Whenyoubringthelargermagnetincloser,thesizeofyourpatternchanges,doesn’tit?Mostpatternshaveatleastone(sometimestwo)stablepatterns,eachofwhichisalocalminimumenergypattern.Thepatternsthatthelittleboatsmakeareverysimilartothecrystalstructuresinsolids.

Noticehowthemagnetboatsrepeleachotherwhentheygettooclose,yettheyholdeachotherinapattern.Atomsdothesamething–theyrepeleachotherwhenyoutrytosquishthemtogether,yetholdtogethertoformmolecules.

Lesson

1. Talktothekidsabouthowtheytookthefirststepintothestrangeworldofmagnetismwhentheyplayedwithmagnetizinganeedleforacompass.

2. Whydomagnetsdowhattheydo?Whatcausesmagnetism?That’sright…becauseofthebehaviorofelectrons.Whenabunchofthosecrazylittleguysgetgoinginthesamedirection,theycreateamagneticfield.

3. Recaptheinversesquarelaw:Asthenorthandsouthsidesofamagnetgetclosertogether,thepullofthemagneticforceisstronger.Thisistypicaloffields.Thecloseryouget,thestrongerthepulloftheforcegets.Thefartherawayyouget,theweakerthepulloftheforcegets.

4. Nowwegettoputalltheseideastogethertofindoutwhatmagnetsandmathhaveincommon.

LabTime


2. Placethemagnetsinatallstack.3. Breakthefoamintosmallpieces,about1‐2”square.4. Usingthehotgluegun,placeadabofhotglueinthecenterofafoamblock.5. Workingquickly,removeonemagnetfromthestackandplaceitrightontothefoam.Gluethemagnetto

thefoam.6. Repeatfortherestofthemagnets,makingsurethattheyareallfacingthesameway(samepolefacingupif

thetopsurfaceisonepole).7. Placethreeofthemagnetsinashallowdishofwatersotheyarefreetofloat.Whathappens?8. Now,takealargemagnetandmoveittowardthefloatingmagnets.Canyoukeeptheminastraightline

usingthelargemagnet?


9. Completethetable.

Exercises

1. Whatshapedothreemagnetsgive?Whyisthisdifferentfromtheshapethatfourmagnetsmake?(Equilateraltriangle.Fourmakesasquare,becausethisistheminimumenergypattern.)

2. Whydothemagnetsflipoverwhenyoufirstplacetheminthewater?(Becausetheyareheavieronthebottomandlighterontop,unlessyourfoamislargeenoughtopreventthemfromflippingover.)

3. Howmanymagnetsmakeahexagon?(Sixandseven–theseventhoneisinthemiddleofthehexagon.)4. Howisthisexperimentlikethecompassexperimentswe’vedonesofar?(Themagnetizedneedleislikea

tinymagnetfloatinginthecupofwater,justliketheseare.Whenyoubringalargemagnetclose,thefloatingmagnetsalignthemselveswiththelargemagnet.)

5. Whydotheboatsrepeleachother,yetstillholdinapattern?(Thefloatingmagnetsrepeleachotherbecausetheyhavethesamepoleorientedup.Yettheholdeachotherinapatternbecauseoftheirinteractingmagneticfields.)



Lesson#8:MagneticBoatsStudentWorksheet

Name______________________________________________________________________

Overview:Todayyougettosplasharoundwithseveralcompassesatonceasyoudiscoverhowmagnetscanbothrepelandattracteachotheratthesametime.

WhattoLearn:Noticehowthemagnetboatsrepeleachotherwhentheygettooclose,yettheyholdeachotherinapattern.Atomsdothesamething–theyrepeleachotherwhenyoutrytosquishthemtogether,yetholdtogethertoformmolecules.

Materials

Shallowdishorpietin Water Foamblocks 6‐10smallmagnets Largemagnet Hotgluegun

LabTime

1. Placethemagnetsinatallstack.2. Breakthefoamintosmallpieces,about1‐2”square.3. Usingthehotgluegun,placeadabofhotglueinthecenterofafoamblock.4. Workingquickly,removeonemagnetfromthestackandplaceitrightontothefoam.Gluethemagnetto

thefoam.5. Repeatfortherestofthemagnets,makingsurethattheyareallfacingthesameway(samepolefacingupif

thetopsurfaceisonepole).6. Placethreeofthemagnetsinashallowdishofwatersotheyarefreetofloat.Whathappens?7. Nowtakealargemagnetandmoveittowardthefloatingmagnets.Canyoukeeptheminastraightline

usingthelargemagnet?8. Completethetable.


MagnetBoatsDataTable

NumberofMagnets Howaremagnetsdistributed?(Whatshapedotheymake?)

2

3

4

5

6

7

8


1. Whatshapedothreemagnetsgive?Whyisthisdifferentfromtheshapethatfourmagnetsmake?

2. Whydothemagnetsflipoverwhenyoufirstplacetheminthewater?

3. Howmanymagnetsmakeahexagon?

4. Howisthisexperimentlikethecompassexperimentswe’vedonesofar?

5. Whydotheboatsrepeleachother,yetstillholdinapattern?


Lesson#9:CurieHeatEngineTeacherSection

ThisisaBonusLab,meaningthatit’sinadditiontotheexperimentsthekidsgettodothroughoutthecourse.Feelfreetoskipthislabifthematerialsareoutofyourbudget,orsaveitasatreatfortheendoftheyear.Youcanalsojustmakeoneanduseitasademopieceforashortlabday.

Overview:We’regoingtoheatamagnetsothatittemporarilylosesitsmagneticpoles,andwatchwhathappensasitcyclesthroughcooling.PierreandMarieCurie’sfirstscientificworkswereactuallyinmagnetism,notchemistry,andtheirpapersinmagneticfieldsandtemperaturewhenamongthefirstnoticedbythescientistsatthetime.


Objectives:MagneticmateriallosesitsabilitytosticktoamagnetwhenheatedtoacertaintemperaturecalledtheCurietemperature.TheCurietemperaturefornickelis380oF,ironis1,420oF,cobaltis2,070oF,andforceramicferritemagnets,itstartsat860oF.


Largeceramicmagnet Tinybeadmagnet Thincopperwire Smoothpenorstraw Candle(withadulthelp) Frameworktoholdthesetup(refertovideo)

LabPreparation

1. Printoutcopiesofthestudentworksheets.2. Watchthevideoforthisexperimenttoprepareforteachingthisclass.Youcanopttobuildasimpleframe

fromacoathanger,orjusthavethekidsholdit.Sincethisexperimentinvolvesfire,Ionlylightthecandleoftheteamthatisdirectlyworkingwithanadult.ThismeansI’vegottorecruitsomehelpduringthisclasstokeepaneyeonthekidsandsuperviselightingofcandles.Parentsareusuallyhappytohelp.

3. Makeoneofthesefirst.Decidewhichkindofframeyou’dliketouse.Ifyouchoosethewaterbottlemethod,you’llwanttwofullwaterbottleswithasmoothpentapedacrossthecaps.Ifyouchoosethewirecoathanger,you’llneedtopracticewithitfirstsoyouknowwhatshapeyou’reaskingthekidstomakewhenit’stimeforthelab.

4. ReadovertheBackgroundLessonReadingbeforeteachingthisclass.



Attheendoftheswingingwire,there’satinybeadmagnet,whichisquitestrongforitssize.Themagnetisattractedtothelargeceramicmagnetandmovestowardit,almosttouchingit.Thecandleheatsupthetinybeadmagnet,causingittotemporarilyloseitsmagnetismbyaddingenergyintotheatomsandrandomizingtheirorientationwithinthemagnet.You’llnoticethatthemagnetquicklyregainsitsmagnetismafteritcools.Whileyoucanpermanentlydestroythemagneticfieldinthebeadmagnet,you’dneedsomethinghotterthanapropanetorchtodoit.

TheCurietemperaturefortheceramicmagnetismuchhigherthanacandlecanproduce,whichiswhythepermanentmagnetisn’taffectedbytheflame.TheCurietemperatureforthetinybeadmagnetisabout600oF,whichiseasilyobtainablebyyourcandle.

Lesson

1. You’llwanttomakeoneoftheseasademopiecetostarttheclassoffwith,sincethisissuchanunusualeffect.Watchthevideosoyoucanseethetinybeadmagnetontheendofthewireswingbackandforthasit’saffectedbytheflame.Talktothekidsaboutwhat’sgoingonasitshappeningandinvitequestions.

2. Ifyoucan’tfindabeadmagnet,theCurietemperaturefortheRadioShackrareearthmagnetsisjustunder600oF,whichalsowithinreachofyourcandle’sheat.Themagnetsarealsoonthesmallsize,sotheytendtoheatupfaster.Youcanbreakamagnetifyouneedasmallerpieceforthisexperiment.

LabTime


2. Watchthevideofirst.Herearethebasicinstructionsfromthevideo.3. Createyourframe.Ifyou’reusingthetwowaterbottledesign,makesuretheyarefullofwater.Spacethem

approximatelysixinchesapartandlayasmoothpenorstrawacrossthecaps.Tapethepenintoplace.4. Insertthewireintoyourbeadmagnetandtwistthewireendbackonitselfsothebeaddoesn’tcomeoff.I

useawirethatdoesn’thaveinsulationsoitwon’tburnwhenintheflame.5. Straightenoutyourwire.6. Placeavotivecandleonthetablebetweenthetwowaterbottles.Iliketodothisonacookiesheetto

protectthedesks.7. Wrapyourwirearoundthepenlooselyseveraltimessothatitcanstillswinglikeapendulumeasilywhile

hangingatthetopofthewickofthecandle.Youwantthebeadmagnettobejusttouchingthetopoftheflamewhenyoulightthecandle.Makesurethepenissupportedwell.

8. Laytheceramicmagnetonitssideacrossonesideofthevotivecandlesothatthebeadmagnetisattractedtoitandsticks.Movethelargemagnetsothatthebeadmagnetisjusttouchingthetopoftheflamewhileit’sstickingtoit.

9. You’llbeadjustingitwhilethecandleislit,sopleasebecareful!Theceramicmagnetretainsheatforalongtimeandwillbehottothetouch,aswillthewireandthebeadmagnet.

10. Haveanadultlightthecandleandhelpthestudentsmaketheproperadjustments.Watchingthevideoagainmayhelp.


Exercises

1. Whydoesthetinymagnetloseitsattractiontothelargemagnet?(Curietemperatureisthetemperatureatwhichaferromagneticmaterialbecomesparamagneticonheatingandtheeffectisreversible.AmagnetwillloseitsmagnetismifheatedabovetheCurietemperature.)

2. Howlongdoesittakefortheattraction‐repulsioncycletorepeat?(Itdependsonthesizeofyourbeadmagnetandthetemperatureofyourflame.Largermagnetstakelongertoheatup.)

3. Drawoutyourexperiment,explaininghowitworksandlabelingeachpart:



Lesson#9:CurieHeatEngineStudentWorksheet

Name______________________________________________________________________

Overview:We’regoingtoheatamagnetsothatittemporarilylosesitsmagneticpoles,andwatchwhathappensasitcyclesthroughcooling.

WhattoLearn:MagneticmateriallosesitsabilitytosticktoamagnetwhenheatedtoacertaintemperaturecalledtheCurietemperature.TheCurietemperaturefornickelis380oF,ironis1,420oF,cobaltis2,070oF,andforceramicferritemagnetsitstartsat860oF.

Materials

Largeceramicmagnet Tinybeadmagnet Thincopperwire Smoothpenorstraw Candle(withadulthelp) Frameworktoholdthesetup

LabTimePleasebeverycarefulwiththislab!Youwillneedadulthelpwiththefire.

1. Yourteacherwillshowyouhowtocreateyourframe.Ifyou’reusingthetwowaterbottledesign,makesuretheyarefullofwaterandspacethemapproximatelysixinchesapartandlayasmoothpenorstrawacrossthecaps.Tapethepenintoplace.

2. Insertthewireintoyourbeadmagnetandtwistthewireendbackonitselfsothebeaddoesn’tcomeoff.Iuseawirethatdoesn’thaveinsulationsoitwon’tburnwhenintheflame.

3. Straightenoutyourwire.4. Placeavotivecandleonthetablebetweenthetwowaterbottles.Iliketodothisonacookiesheetto

protectthedesks.5. Wrapyourwirearoundthepenlooselyseveraltimessothatitcanstillswinglikeapendulumeasilywhile

hangingataheightatthetopofthewickofthecandle.Youwantthebeadmagnettobejusttouchingthetopoftheflamewhenyoulightthecandle.Makesurethepenissupportedwell.

6. Laytheceramicmagnetonitssideacrossonesideofthevotivecandlesothatthebeadmagnetisattractedtoitandsticks.Movethelargemagnetsothatthebeadmagnetisjusttouchingthetopoftheflamewhileit’sstickingtoit.

7. You’llbeadjustingitwhilethecandleislit,sopleasebecareful!Theceramicmagnetretainsheatforalongtimeandwillbehottothetouch,aswillthewireandthebeadmagnet.

8. Haveanadultlightyourcandleandhelpyoumaketheproperadjustments.Watchingthevideoagainmayhelp.


Exercises


1. Whydoesthetinymagnetloseitsattractiontothelargemagnet?

2. Howlongdoesittakefortheattraction‐repulsioncycletorepeat?

3. Drawoutyourexperiment,explaininghowitworksandlabelingeachpart:


Lesson#10:LinearAcceleratorTeacherSection

ThisisaBonusLab,meaningthatit’sinadditiontotheexperimentsthekidsgettodothroughoutthecourse.Feelfreetoskipthislabifthematerialsareoutofyourbudget,orsaveitasatreatfortheendoftheyear.Youcanalsojustmakeoneanduseitasademopieceforarainyday.ThisprojectisalsofeaturedintheScienceFairProjectsample.

Overview:Linearaccelerators(alsoknownasa”linac”)usedifferentmethodstomoveparticlestoveryhighspeeds.Onewayisthroughinduction,whichisbasicallyapulsedelectromagnet.We’regoingtouseaslowinputspeedandsuper‐strongmagnetsandmultiplytheeffecttocauseaballbearingtoshootacrossthefloorathighspeed.

SuggestedTime:30‐90minutes(thislabhastwoparts,thesecondofwhichisoptional)

Objectives:Studentswilllearnhowtomeasure,takedata,andmakesteelballbearingsflyaroundtheroomusingmomentumandmagnetism.


Woodorplasticrulerwithagroovedownthecenter,12”long Eightthickrubberbandsorepoxyforapermanentmount Foursuper‐strongmagnets(try12mmor½”neodymiummagnets) Ninesteelballbearings(1/2”,5/8”,orothersizes) Measuringtape

LabPreparation

1. Printoutcopiesofthestudentworksheets.2. Watchthevideoforthisexperimenttoprepareforteachingthisclass.3. ReadovertheBackgroundLessonReadingbeforeteachingthisclass.4. Ifyou’reshortonmeasuringtapes,makeastartlinewithchalkormaskingtapeandlayacoupleof

measuringtapesextendedtheirfulllength,startingatthestartline.Thiswillenablethestudentstoquicklymeasurehowfartheirballgoeswithjustaquickglance.

5. Maketheadvancedmodelaheadoftime,especiallyifyou’renotplanningtodothesecondpartofthelab.Thisway,youcanuseitasateachingpieceforthekidsanddemonstratehowtousemagnetismandmomentumtopropelparticlesandobjectsathighspeeds.


Thereareseveraldifferenttypesofmagnets.Permanentmagnetsarematerialsthatstaymagnetized,nomatterwhatyoudotothem…evenifyouwhackthemonthefloor(whichyoucandowithamagnetizednailtodemagnetizeit).Youcantemporarilymagnetizecertainmaterials,suchasiron,nickel,andcobalt.Andanelectromagnetisbasicallyamagnetthatyoucanswitchonandoffandreversethenorthandsouthpoles.

Thestrengthofamagneticfieldismeasuredin“Gauss.”TheEarth’smagneticfieldmeasures0.5Gauss.Typicalrefrigeratormagnetsare50Gauss.Neodymiummagnets(liketheoneswe’regoingtouseinthisproject)measure


at2,000Gauss.Thelargestmagneticfieldshavebeenfoundarounddistantmagnetars(neutronstarswithextremelypowerfulmagneticfields),measuringat10trillionGauss.(Aneutronstariswhat’sleftoverfromcertaintypesofsupernovae,andtypicallythesizeofManhattan.)

Inthisexperiment,themetalballbearingisseriouslyattractedtoyourmagnets,andthispullintensifiestheclosertheballgetstothemagnet(inverse‐squarelaw).Whentheballsmacksintothemagnet,theenergywavefromtheimpactzipsthroughthemagnetandattachedballbearingsuntilitknocksthefurthestballfree,whichhastheleastmagneticpullonitbecauseit’sfurthestfromthemagnet.Ifitwasn’t,itwouldbesloweddownandpossiblyreattachedtothemagnetitjustbrokeawayfrom.

Witheachimpact,there’sanincreaseinvelocity.Imagineifyouhadahundredofthesethingslinedup…howfastcouldyougetthatlastballbearinggoing?

Aftereachfiring,youhavetoresetyoursystem,andchancesareittakesabitofefforttopulltheballbearingsfromthemagnets!Youareprovidingtheenergythatgetsreleasedduringeachcollisionandaddstothevelocityoftheballbearings.

Lesson

1. Constructionnote:Ifyouplanonhavingasetofthesetouseforyears,permanentlystickthemagnetstotherulerusingepoxyorJBWeld.Whenyoupermanentlymountthemagnets,thisexperimentissaferforthekidstohandlesincethemagnetscan’tslipoutfromundertherubberbandandsquashfingersorbreakintopieces.

2. Thislabhastwosections.Feelfreetostopafterthefirstpart,orgoontothesecond.It’sreallyuptoyou.Thefirstlabisfairlyeasyandstraightforwardwithoutalotoffuss.Forthefirstpart,youdonotneedrubberbandsorepoxy,sinceyouonlyneedonemagnetperlabgroup,andthesetupdoesn’tneedtobepermanentlymounted.Thesecondpartofthelabdoesrequireadditionaladulthelptoseparatethemagnetsandgetthemunderthestiffrubberbands.Youcanopttomakeoneoftheadvancedmodelsinthesecondpartforyourselfasademopiecewhileyouleadthestudentsthroughthefirstpart.

LabTime

1. Reviewtheinstructionsontheirworksheetsandthenbreakthestudentsintotheirlabgroups.Handeachgrouptheirmaterials.Thislabhastwoparts.

Part1:Single‐magnetdesign:Thisisagoodonetostartwith,especiallyifthemagnetsaretoostrongforthekidstoplaywith.

1. Thevideoshowsusingapapertoweltube,whichyoucanuseifyouwanttoskipthemeasurementsandjusthavefun.Otherwise,substitutetherulerforthetube.

2. Placetheruleronthetable.3. Putamagnetatthe6”markontheruler.Ifyou’vefoundastrongneodymiummagnet,youonlyneedone

magnet,notthefourasshowninthevideo.4. Addfourballbearingsinthegrooveontherulerinaline,withoneendtouchingthemagnet.Theballs

shouldextendpastthe7”mark.5. Propupthe0”markslightlywithathinbookorblock(orjustliftitabitwithyourfinger).6. Placeafifthballbearingonthe0”markandletgo.Whathappened?7. Completethetable.


Part2:Multiple‐magnetdesign:Thisdesignisgoodforadvancedstudentswhohavecompletedthefirstpartandwanttounderstandhowaddingadditionalmagnetsmultipliestheeffect.

1. Takeyourrulerandfindthe11”mark.Wrapyourfirstrubberbandstronglyaroundtheruleratthismark.2. Wrapasecondrubberbandatthe8”mark.3. Wrapthethirdatthe5”mark.4. Wrapthefourthatthe2”mark.5. Carefullystackyourmagnets.Beverycarefulbecauseiftheysnaptogether,theywillbreak.6. Takethefirstoffthestack,keepingtheorientationexactlythesameasitwasinthestack.Wearegoingto

separatethemagnetsfromthestackbutkeeptheminexactlythesamedirectiontheyarein.Ifyoumixupthenorth‐southpoleorientation,yourlinacwon’twork.

7. Slidethemagnetunderthefirstrubberband.Havethemagnetstraddlethe11”mark.Thiswillbeimportantlaterwhenwetakemeasurements.

8. Slidethesecondmagnetunderthesecondrubberband.Keepthemagnetsfacingthesamewayasyouwork!

9. Slidethethirdmagnetunderthethirdrubberband.Dothesamewiththefourth.10. Addasecondrubberbandtoeachmagnettosecureitintoplace.11. Carefullyplacetwoballbearingsononesideofeachmagnetinalineinthegrooveoftheruler.Yourlast

ballbearingshouldbeatthe12”mark.12. Lookatyourruler.Youshouldhaveamagnetatthe2”mark,followedbytwoballbearingsinthegroove.

Thenyoushouldhaveanothermagnetwithtwomoreballbearings,athirdmagnetwithanothertwoballbearings,andafourthmagnetwiththelasttwoballbearingsendingattheedgeoftheruler.

13. Propupthe0”markontherulerwithathinbook,block,oryourfinger.14. Takeyourverylast,ninthballbearing.Placeitatthe0”markandletgo.Whathappened?Writeithere:15. Drawwhatyourrulerlookslikebeforeimpact:16. Drawwhatyourrulerlookslikeafterimpact(wherearetheballbearingsnow?):17. Completethetable.


Exercises

1. Doesitreallymatterwhereyoustartthefirstballbearing?Ifso,doesitmattermuch?(Refertoyourdatatable.)

2. Whydoesonlythelastballgoflyingaway?Whydon’ttheothersbreakawayaswell?(Haveyouevershotabilliardballtowardanotheronapooltableandwatchedthefirstonestopwhilethesecondgoesflying?Thishastodowithaconceptknownasmomentum.Theballfurthestfromthemagnetbreaksfreebecauseithasenoughmomentum(whichisdirectlyrelatedtospeed)toescapethemagneticfieldofthestrongmagnet.)

3. Whathappensifyoutrythisexperimentwithoutthemagnets?Canyougetoneballbearingtotransferallitsmomentumtoasecondone?(Itworks,buttheballdoesn’ttravelasfar.Themagnetsprovideextraenergy(speed)totheincomingball,whichistransferredtothebreakawayballonimpact.)

4. Howmanyinchesdidthefirstinitialball(theoneyouletgoof)travel?(Refertodatatable.)5. Howmanyinchesdidthelastball(theonethatdetachedfromthemagnet)travel?(Refertodatatable.)6. Whydidweusefourmagnetsinthesecondlab?Whatdidthatdo?(Witheachimpact,there’sanincrease

inspeed.Theadvancedmodelislikeliningupfourofthesimplemodelsallinarow.)



Lesson#10:LinearAcceleratorStudentWorksheet

Name______________________________________________________________________

Overview:Linearaccelerators(alsoknownasa”linac”)usedifferentmethodstomoveparticlestoveryhighspeeds.Onewayisthroughinduction,whichisbasicallyapulsedelectromagnet.We’regoingtouseaslowinputspeedandsuper‐strongmagnetsandmultiplytheeffecttocauseaballbearingtoshootacrossthefloorathighspeed.

WhattoLearn:Todayyou’regoingtodoanaward‐winningproject(yes,loadsofstudentshaveusedthisexperimentinsciencefairsandtakenhomefirstprize!)thatwillteachyouhowtomeasure,calculate,recorddata,andmakesteelballbearingsflyaroundtheroomusingmomentumandmagnetism.

Materials

Woodorplasticrulerwithagroovedownthecenter,12”long Eightthickrubberbandsorepoxyforapermanentmount Foursuper‐strongmagnets(try12mmor½”neodymiummagnets) Ninesteelballbearings(1/2”,5/8”,orothersizes) Measuringtape

LabTime:Yourteacherwillletyouknowwhichpartsofthelabyouaretocomplete.

Part1:Single‐magnetdesign:

1. Placetheruleronthetable.2. Putamagnetatthe6”markontheruler.Ifyou’vefoundastrongneodymiummagnet,youonlyneedone

magnet,notthefourasshowninthevideo.3. Addfourballbearingsinthegrooveontherulerinaline,withoneendtouchingthemagnet.Theballs

shouldextendpastthe7”mark.4. Propupthe0”markslightlywithathinbookorblock(orjustliftitabitwithyourfinger).5. Placeafifthballbearingonthe0”markandletgo.Whathappened?6. Completethetableonthenextpage.


SimpleLinearAcceleratorDataTable

You’llwanttopropupyourruleratthesameheightforallthedatayoumeasure,oryou’llhavetorecordtherulerangleaswellwitheachtrialrun.Also,notehowfartheinitialballhastotravel.Ifyourmagnetisat6”andyouletgoatthe2”mark,thenittravels4”.Soyou’dwrite4”inthe“DistanceInitialBallTraveled”.

Trial# DistanceInitialBallTraveled DistanceBreakawayBallTraveled (inches) Circleone:(inchesorfeet)

1

2

3

4

5

6

7

8

9

10


Part2:Multiple‐magnetdesign:

1. Takeyourrulerandfindthe11”mark.Wrapyourfirstrubberbandstronglyaroundtheruleratthismark.2. Wrapasecondrubberbandatthe8”mark.3. Wrapthethirdatthe5”mark.4. Wrapthefourthatthe2”mark.5. Carefullystackyourmagnets.Beverycarefulbecauseiftheysnaptogether,theywillbreak.6. Takethefirstoffthestack,keepingtheorientationexactlythesameasitwasinthestack.Wearegoingto

separatethemagnetsfromthestackbutkeeptheminexactlythesamedirectiontheyarein.Ifyoumixupthenorth‐southpoleorientation,yourlinac(linearaccelerator)won’twork.

7. Slidethemagnetunderthefirstrubberband.Havethemagnetstraddlethe11”mark.Thiswillbeimportantlaterwhenwetakemeasurements.

8. Slidethesecondmagnetunderthesecondrubberband.Keepthemagnetsfacingthesamewayasyouwork!

9. Slidethethirdmagnetunderthethirdrubberband.Dothesamewiththefourth.10. Addasecondrubberbandtoeachmagnettosecureitintoplace.11. Carefullyplacetwoballbearingsononesideofeachmagnetinalineinthegrooveoftheruler.Yourlast

ballbearingshouldbeatthe12”mark.12. Lookatyourruler.Youshouldhaveamagnetatthe2”mark,followedbytwoballbearingsinthegroove.

Thenyoushouldhaveanothermagnetwithtwomoreballbearings,athirdmagnetwithanothertwoballbearings,andafourthmagnetwiththelasttwoballbearingsendingattheedgeoftheruler.

13. Propupthe0”markontherulerwithathinbook,block,oryourfinger.14. Takeyourverylast,ninthballbearing.Placeitatthe0”mark,andletgo.Whathappened?Writeithere:

________________________________________________________________________________________________________

________________________________________________________________________________________________________

________________________________________________________________________________________________________

________________________________________________________________________________________________________


15. Drawwhatyourrulerlookslikebeforeimpact:

16. Drawwhatyourrulerlookslikeafterimpact(wherearetheballbearingsnow?):

17. Completethetableonthenextpage.


AdvancedLinearAcceleratorDataTable

Notethatwe’remeasuringtwothingsforthebreakawayball:howlongittakesfortheballtotravelsixfeet,whichismeasuredinseconds,andalsohowfaritgoesuntilitstopsonitsown,measuredindistance.Assignonepersontoeachmeasurementtask:distanceortime.

Forthetimemeasurement,you’llwanttouseyourtapemeasuretomarkhowfarsixfeetisbeforeyoustart,andthenplacetheendofyourruleratthestartline.Assoonasthebreakawayballleavestheruler,starttiming.Whenitcrossesthefinishlinesixfeetaway,stoptimingandrecordthisnumberinthethirdcolumn:‘TimeBreakawayBallTraveled6Feet’.

Tofigureouthowfastyourballisgoing,divide6feetbythetimeyourecorded.Ifittookyourballtwosecondstogosixfeet,thenthespeedis3feetpersecond.

You’llwanttopropupyourruleratthesameheightforallthedatayoumeasure,oryou’llhavetorecordtherulerangleaswellwitheachtrialrun.Alsonotehowfartheinitialballhastotravel.Ifyourfirstmagnetisat2”andyouletgoatthe0.5”mark,thenittravels1.5”.Soyou’dwrite1.5”inthe“DistanceInitialBallTraveled”.

Trial#DistanceInitialBallTraveled

TimeBreakawayBallTraveled6feet

TotalDistanceBreakawayBallTraveled

CalculatedAverageSpeed:Speed=6feet/Time

(inches) (seconds) Circleone:(feetorinches) (feetpersecond)

1

2

3

4

5

6

7

8

9

10


Exercises


1. Doesitreallymatterwhereyoustartthefirstballbearing?Ifso,doesitmattermuch?

2. Whydoesonlythelastballgoflyingaway?Whydon’ttheothersbreakawayaswell?

3. Howmanyinchesdidthefirstinitialball(theoneyouletgoof)travel?

4. Howmanyinchesdidthelastball(theonethatdetachedfromthemagnet)travel?

5. Whydidweusefourmagnetsinthesecondlab?Whatdidthatdo?


Lesson#11:EarthPulseTeacherSection

ThisisaBonusLab,meaningthatit’sinadditiontotheexperimentsthekidsgettodothroughoutthecourse.Feelfreetoskipthislabifthematerialsareoutofyourbudget,orsaveitasatreatfortheendoftheyear.Youcanalsojustmakeoneanduseitasademopiecetokeepinyourclassroom,becauseonceit’ssetup,itgoesforever.

Overview:Whenyoustareatacompass,theneedlethatindicatesthemagneticfieldfromtheEarthappearstostandstill,butwe’regoingtofindhowitfluctuatesandmovesbycreatingasuper‐sensitiveinstrumentusingeverydaymaterials(forcomparison,youwouldspendmorethan$100forascientificinstrumentthatdoesthesamething).


Objectives:KidswilllearnhowtoamplifytinypulsesintheEarth’smagneticfieldusingalaser.


Indexcardorscrapofcardboard 2smallmirrors 2rareearthmagnets Nylonfilament(thinnylonthreadworks,too) 4doughnutmagnets Laserpointer(anykindwillwork–eventhecheapkey‐chaintype) Cleanglassjar(pickle,jam,mayo,etc…anykindofjarthat’sheavysoitwon’tknockovereasily) Woodenspring‐typeclothespin Hotgluegun,scissorsandtape

LabPreparation

1. Printoutcopiesofthestudentworksheets.2. Watchthevideoforthisexperimenttoprepareforteachingthisclass.3. ReadovertheBackgroundLessonReadingbeforeteachingthisclass.4. Precutthenylontwineinto12”pieces,oneforeachlabgroup.


Thereasonthisprojectworksisbecauseoftinymagneticdisturbancescausedbytheripplesintheionosphere.Althoughthesedisturbanceshappenallthetimeandonaverysmallscale(usuallyonly1/10,000thoftheEarth’smagnetismstrength),we’llbeabletopickthemupusingthisincrediblysimpleproject.Yourreflectedlaserbeamactslikeanamplifierandpicksupthemovementfromthemagnetintheglass.

Constructiontipforexperiment:Youneedtouseafilamentthatdoesn’tcarehowhotorhumiditisoutside,sousingoneofthehairsfromyourheaddefinitelywon’twork.Cottontendstobetoostretchyaswell.Professionalsusefinequartzfibers(whichareamazinglystrongandreallydon’tcareabouttemperatureorhumidity).Try


extractingasinglefilamentfromamulti‐strandednylontwinelengthabout30″long.Ifyouhappentohaveafineselectionofnylontwinehandy,grabtheonethatisabout25microns(0.01″)thick.Otherwise,justgetthethinnestoneyoucanfind.

Alsonotethatbig,powerfulmagnetswillnotrespondquickly,soyouneedalightweight,powerfulmagnet.TryfindingasetofrareearthmagnetsfromRadioShackorthehardwarestore.

Youcanwalkaroundwithyournewinstrumentandyou’llfindthatit’sasaccurateasacompassandwillindicatenorth.Youprobablywon’tseemuchoscillationasyoudothis.BecausetheEarthhasalargemagneticfield,youhaveto“tare”theinstrument(setitto“zero”)soitcanshowyouthesmallerstuff.Usethedoughnutmagnetsabout30centimetersawayasshowninthevideo.

Lesson

1. Youcantapeawoodenclothespindowntothetableandinsertyourlaserpointerinside–thejawswillpushthebuttonofthelaserdownsoyoucanwatchyourinstrumentandtakeyourmeasurements.Whenyou’reready,tapeasheetofpapertothewallwhereyourreflectedbeam(reflectedfromthemirror,nottheglass…therewillbetworeflectedbeams!)hitsthewallandmarkwhereithits.Overperiodsofsecondstominutes,you’llseedeflectionsandoscillations(wigglesbackandforth)–youaretakingtheEarth’smagneticpulse!

2. Inorderforthisexperimenttoworkproperly,ALLmagnets(includingthepennydescribedbelow)needtobeinthesameplane.Thatis,theyallneedtobethesameheightfromtheground.Youcan,ofcourse,rotatetheentiresetup90degreestoinvestigatethemagneticripplesintheotherplanesaswell!

3. Tomakethisinstrumentevenmoresensitive,glueacopperpenny(makesureit’smintedbefore1982,oryou’llgetanalloy,notcopper,penny)totheglassjarjustbehindthemagnets(oppositethelaser).Whenyourmagnetsmovenow,theywillinduceeddycurrentsinthepennythatwillinducea(small)magneticfieldoppositetherotationofthemagnetstodampenout“noise”oscillation.Inshort,addapennytotheglasstomakeyourinstrumenteasiertoread.

LabTime


2. Watchthevideofirstandmakeasample.Herearethestepsfromthevideo:3. Sandwichthetwinebetweenthetworareearthmagnets.Thesearethestrongermagnets.4. Useatinydabofglueononeofthemagnetsandattachamirrortothemagnet.Dothisontheothersidefor

thesecondmagnetandmirror.5. Lowerthemirror‐magnetsintothecontainer,leavingithanginganinchabovethebottomofthejar.Cutthe

twineatthemouthlevelofthecontainer.6. Gluethetopofthetwinetothebottomofthelid,rightinthecenter.7. Whenthegluehasdried,placeyourmirror‐magnetsinsidethejarandclosethelid.Makesurethatthe

mirror‐magnetsdon’ttouchthesideofthejar,andarefreetorotateandmove.8. You’vejustbuiltacompass!Thesmallmagnetswillalignwiththeearth’smagneticfield.Slowlyrotatethe

jar,andwatchtoseethatthemirror‐magnetsinsidealwaysstayinthesameconfiguration,justliketheneedleofastandardcompass.

9. Setyournewcompassasideanddon’ttouchit.Youwantthemirror‐magnetstosettledownandgetverystill.


10. Youaregoingtobuildthemagnetarraynow.Stackyourfourdoughnutmagnetstogetherinatallstack.11. Foldyourindexcardinhalf,andthenopenitbackup.Ononesideofthecreaseyou’regoingtoglueyour

magnets.Whenthemagnetsareattached,you’llfoldthecardoversothatitsitsonthetablelikeagreetingcardwiththemagnetsfacingyourglassjar.

12. Tapeyourindexcarddowntothetableasyoubuildyourmagnetarray.(Otherwisethepaperwilljumpupmid‐waythroughandruinyourgluingwhileyouareworking.)

13. Placeastripofglueonthebottommagnetofyourstackandpressitdownontothepaper,gluingitintoplace.

14. Liftthestackoff(thebottommagnetshouldstayputonthepaper)andplaceglueonthebottommagnet.Gluethisonenexttothefirst.

15. Continuewiththearraysoyouhavearectangle(orsquare)arrangementofmagnetswiththeirpolesorientedthesameway.Don’tflipthemagnetsasyougluethem,oryou’llhavetostartovertomakesuretheyarelinedupright.

Sinceweliveinagiganticmagneticfieldthatis10,000timesmorepowerfulthanwhattheinstrumentisdesignedtomeasure,wehaveto“zeroout”theinstrument.It’slikeusingthe“tare”or“zero”functiononascale.Whenyouputaboxonascaleandpush“tare,”thenthescalereadszerosoitonlymeasureswhatyouputinthebox,notincludingtheweightofthebox,becauseit’ssubtractingtheweightoftheboxoutofthemeasurement.That’swhatwe’regoingtodowithourinstrument:WeneedtosubtractouttheEarth’smagneticfieldsowejustgetthetinyfluctuationsinthefield.

16. Placeyourinstrumentawayfromanythingthatmightaffectit,likemagnetsoranythingmadefrommetal.17. Foldthecardbackinhalfandstanditonthetable.We’renormallygoingtokeepthearrayawayfromthe

jar,orthemagnetarraywillinfluencethemirror‐magnetsjustlikebringingamagnetclosetoacompassdoes.Buttozerooutourinstrument,weneedtofigureoutwhatthedistanceisthatthearrayneedstobeinordertocancelouttheEarth’sfield.

18. Bringthearrayclosetoyourjar.Youshouldseethemirror‐magnetsalignwiththearray.19. Slowlypullthemagnetarrayawayfromthecompasstoapointwhereifitwereanycloser,themirror‐

magnetswouldstarttofollowit,butanyfurtherawayandnothinghappens.It’sabout12inchesaway.Measurethisforyourexperimentandwriteitonyourarrayorjarsoyoucanquicklyrealignifneededinthefuture.

20. Insertyourlaserpointerintotheclothespinsothatthejawspushthebuttonandkeepthelaseron.Placeitatleastthesamedistanceawayasthearray.Youmighthavetopropthelaseruponsomethingtogettheheightjustrightsoyoucanaimthelasersothatithitsthemirrorinside.(Notethatyou’llhaveareflectionfromtheglassaswell,butitwon’tbenearlyasbright.)

21. Findwherethelaserbeamisreflectedoffthemirrorandhitsthewallinyourroom.Walkoverandtapeasheetofpapersothatthedotisinthemiddleofthepaper.Useapenanddrawrightontopofthedot,andmarkitwithtoday’sdate.

22. Doyounoticeifitmovesorifitstaysput?Sometimesthedotwillmoveovertime,andothertimesthedotwillwiggleandmovebackandforth.Thewiggleswilllastacoupleofsecondstoacoupleofminutes,andthosearetheoscillationsandfluctuationsyouarelookingfor!

23. Tapearulernexttothedotsoyoucanmeasuretheamountofmotionthatthedotmakes.Doesitmovealotoralittlewhenitwiggles?Twoinchesorsix?

Exercises


1. Doestheinstrumentworkwithoutthemagnetarray?(Yes,butonlyasacompass.)2. Whydidweusethestrongermagnetsinsidetheinstrument?(Smalllightweightmagnetsareneededtobe

usedtomovethemirrorsanddetectthefluctuations.)3. Whichplanetwouldthisinstrumentprobablynotworkon?(VenusandMars)



Lesson#11:EarthPulseStudentWorksheet

Name______________________________________________________________________

Overview:Whenyoustareatacompass,theneedlethatindicatesthemagneticfieldfromtheEarthappearstostandstill,butwe’regoingtofindhowitfluctuatesandmovesbycreatingasuper‐sensitiveinstrumentusingeverydaymaterials(forcomparison,youwouldspendmorethan$100forascientificinstrumentthatdoesthesamething).

WhattoLearn:TodayyougettolearnhowtoamplifytinypulsesintheEarth’smagneticfieldusingalaserandacoupleofmagnets.It’saverycoolexperiment,butitdoestakepatiencetomakeitworkright.

Materials

Indexcardorscrapofcardboard 2smallmirrors 2rareearthmagnets Nylonfilament(thinnylonthreadworks,too) 4doughnutmagnets Laserpointer(anykindwillwork–eventhecheapkey‐chaintype) Cleanglassjar(pickle,jam,mayo,etc…anykindofjarthat’sheavysoitwon’tknockovereasily) Woodenspring‐typeclothespin Hotgluegun,scissorsandtape

LabTime

1. Sandwichthetwinebetweenthetworareearthmagnets.Thesearethestrongermagnets.2. Useatinydabofglueononeofthemagnetsandattachamirrortothemagnet.Dothisontheotherside

forthesecondmagnetandmirror.3. Lowerthemirror‐magnetsintothecontainer,leavingthemhanginganinchabovethebottomofthejar.

Cutthetwineatthemouthlevelofthecontainer.4. Gluethetopofthetwinetothebottomofthelid,rightinthecenter.5. Whenthegluehasdried,placeyourmirror‐magnetsinsidethejarandclosethelid.Makesurethatthe

mirror‐magnetsdon’ttouchthesideofthejar,andarefreetorotateandmove.6. You’vejustbuiltacompass!Thesmallmagnetswillalignwiththeearth’smagneticfield.Slowlyrotatethe

jar,andwatchtoseethatthemirror‐magnetsinsidealwaysstayinthesameconfiguration,justliketheneedleofastandardcompass.

7. Setyournewcompassasideanddon’ttouchit.Youwantthemirror‐magnetstosettledownandgetverystill.

8. Youaregoingtobuildthemagnetarraynow.Stackyourfourdoughnutmagnetstogetherinatallstack.9. Foldyourindexcardinhalf,andthenopenitbackup.Ononesideofthecrease,you’regoingtoglueyour

magnets.Whenthemagnetsareattached,you’llfoldthecardoversothatitsitsonthetablelikeagreetingcardwiththemagnetsfacingyourglassjar.


10. Tapeyourindexcarddowntothetableasyoubuildyourmagnetarray.(Otherwisethepaperwilljumpupmid‐waythroughandruinyourgluingwhileyouareworking.)

11. Placeastripofglueonthebottommagnetofyourstackandpressitdownontothepaper,gluingitintoplace.

12. Liftthestackoff(thebottommagnetshouldstayputonthepaper)andplaceglueonthebottommagnet.Gluethisonenexttothefirst.

13. Continuewiththearraysoyouhavearectangle(orsquare)arrangementofmagnetswiththeirpolesorientedthesameway.Don’tflipthemagnetsasyougluethem,oryou’llhavetostartovertomakesuretheyarelinedupright.

Sinceweliveinagiganticmagneticfieldthatis10,000timesmorepowerfulthanwhattheinstrumentisdesignedtomeasure,wehaveto“zeroout”theinstrument.It’slikeusingthe“tare”or“zero”functiononascale.Whenyouputaboxonascaleandpush“tare,”thenthescalereadszerosoitonlymeasureswhatyouputinthebox,notincludingtheweightofthebox,becauseit’ssubtractingtheweightoftheboxoutofthemeasurement.That’swhatwe’regoingtodowithourinstrument:WeneedtosubtractouttheEarth’smagneticfieldsowejustgetthetinyfluctuationsinthefield.

14. Placeyourinstrumentawayfromanythingthatmightaffectit,likemagnetsoranythingmadefrommetal.15. Foldthecardbackinhalfandstanditonthetable.We’renormallygoingtokeepthearrayawayfromthe

jar,orthemagnetarraywillinfluencethemirror‐magnetsjustlikebringingamagnetclosetoacompassdoes.Buttozerooutourinstrument,weneedtofigureoutwhatthedistanceisthatthearrayneedstobeinordertocancelouttheEarth’sfield.

16. Bringthearrayclosetoyourjar.Youshouldseethemirror‐magnetsalignwiththearray.17. Slowlypullthemagnetarrayawayfromthecompasstoapointwhereifitwereanycloser,themirror‐

magnetswouldstarttofollowit,butanyfurtherawayandnothinghappens.It’sabout12inchesaway.Measurethisforyourexperimentandwriteitonyourarrayorjarsoyoucanquicklyrealignifneededinthefuture.

18. Insertyourlaserpointerintotheclothespinsothatthejawspushthebuttonandkeepthelaseron.Placeitatleastthesamedistanceawayasthearray.Youmighthavetopropthelaseruponsomethingtogettheheightjustrightsoyoucanaimthelasersothatithitsthemirrorinside.(Notethatyou’llhaveareflectionfromtheglassaswell,butitwon’tbenearlyasbright.)

19. Findwherethelaserbeamisreflectedoffthemirrorandhitsthewallinyourroom.Walkoverandtapeasheetofpapersothatthedotisinthemiddleofthepaper.Useapenanddrawrightontopofthedot,andmarkitwithtoday’sdate.

20. Doyounoticeifitmovesorifitstaysput?Sometimesthedotwillmoveovertime,andothertimesthedotwillwiggleandmovebackandforth.Thewiggleswilllastacoupleofsecondstoacoupleofminutes,andthosearetheoscillationsandfluctuationsyouarelookingfor!

21. Tapearulernexttothedotsoyoucanmeasuretheamountofmotionthatthedotmakes.Doesitmovealotoralittlewhenitwiggles?Twoinchesorsix?


Exercises


1. Doestheinstrumentworkwithoutthemagnetarray?

2. Whydidweusethestrongermagnetsinsidetheinstrument?

3. Whichplanetwouldthisinstrumentprobablynotworkon?


Lesson#12:FerrofluidTeacherSection

ThisisaDemonstrationLab,meaningthatit’sanexperimentyoudoinfrontofthekids.Ifyouprefer,youcanpurchaseapremadeferrofluidkit,butIprefertoshowthekidswherethefluiditselfreallycomesfromsoit’snotsuchamysteryafterwe’redone.Iusuallyhavecommerciallyavailableferrofluidalsotoplaywithandcompareafterwe’vemadeourown.Feelfreetoskipthislabifthematerialsareoutofyourbudget,orsaveitasatreatfortheendoftheyear.You’llgetlotsofooh‐ahhsifyouperformthisduringParentNightoraspecialschoolfunction.

Overview:Ferrofluidsarewhatscientistscall“colloidalsuspensions,”whichmeansthatthesubstancehaspropertiesofbothsolidmetalandliquidwater(oroil),anditcanchangephaseeasilybetweenthetwo.Becauseferrofluidscanchangephaseswhenamagneticfieldisapplied,you’llfindferrofluidsusedasseals,lubricants,andformanyotherengineering‐relateduses.


Objectives:Thekidswillgettherareopportunitytowatchsomethingtrulyamazingwithoutmakingamess.


Oldtonercartridgefromalaserprinterorcopymachine Strongmagnet(neodymiummagnetsworkbest) Paperornewspaper Babyoilorvegetableoil Plasticbag Metalboltwithnutandlargewasher Disposableplasticcupwithlid Popsiclestick Medicinedropper Glovesandgoggles Adulthelp

LabPreparation

1. Printoutcopiesofthestudentworksheets.2. Watchthevideoforthisexperimenttoprepareforteachingthisclass.3. ReadovertheBackgroundLessonReadingbeforeteachingthisclass.4. Thismayseemobvious,butunlessyou’reafly‐by‐the‐seat‐of‐your‐pantstypeofperson,youmaywantto

dothisoneathomebeforeperforminginfrontofyourstudents.



Theinkinsideyourtonercartridgeispowderedink.Evenanemptycartridgewillhaveextrapowderedinkinside.Theinkhaslittlebitsofironmixedinwiththeink.Ifyouextracttheinkandmixitwithoil,youcanmakeyourownferrofluid.

Aferrofluidbecomesstronglymagnetizedwhenplacedinamagneticfield.Thisliquidismadeupofverytiny(10nanometersorless)particlescoatedwithanti‐clumpingsurfactantsandthenmixedwithwater(orsolvents).Theseparticlesdon’t“settleout”butratherremainsuspendedinthefluid.

Theparticlesthemselvesaremadeupofmagnetite,hematiteoriron‐typesubstance.

Ferrofluidsdon’tstaymagnetizedwhenyouremovethemagneticfield,whichmakesthem“super‐paramagnets”ratherthanferro‐magnets.FerrofluidsalsolosetheirmagneticpropertiesatandabovetheirCurietemperaturepoints.

Engineeringandscientistsuseferrofluidstomakealiquidsealinharddrivesaroundthespinningdiskstokeepoutdustandgrit(harddrivesmustbekeptexceptionallyclean!).Theydothisbyaddingalayerofferrofluidbetweentherotatingshaftandmagnetswhichsurroundtheshaft.

Youcanalsouseferrofluidstoreducefriction,thewayiceandwaterareusediniceskatingrinks.Ifyoucoatastrongmagnetwithferrofluid,youcangetittoglideacrossasmoothsurfacelikeahockeypuck.NASAusesferrofluidsintheflightinstrumentsforspacecraft,also!

Eachparticleofferrofluidislikeaeachgrainoramicro‐magnet,whichnotonlyinteractswithmagneticfields,butalsowithlight.

Withloudspeakers,thelargemagnetsthatinteractwiththecoiloftenheatup.Ifwereplacethemagnetwithferrofluid(whichisaliquid,remember!)itwillactivelyconducttheheatawayfromthecoilandcoolitdownbecausecoldferrofluidismorestronglyattractedthanhot,andthusthecoolerfluidflowstowardthecoil,andthewarmerfluidmovesawayfromthecoil.

Lesson

1. Thevideoontonercartridgesandhowtomakeyourownhomemadeferrofluid.It’sabitlongerthanourusualvideo,butwethoughtyou’denjoytheextracontent.

2. Ifyouworkwithtoner,youwillmakeanabsolutemess.Itwillgetinplacesyouneverthoughtpossible,whichiswhythislabisperfectasademonstration.Yougettobeamessandkidscangiggleandwatchasyoudothisexperimentinfrontofthem.Wearoldclothes,goggles,gloves,andbepreparedtohavealotoffun.

LabTime

1. Reviewtheinstructionsontheirworksheetsandthenhavethestudentsgatheraroundwhileyouperformthedemonstrationlab.

2. Watchthevideoandseewhereyouneedtopunchholes(ifneeded)inyourtoner.3. Wearinggloves,removeasmuchofthepowderedinkasyoupossiblycanontoasheetofpaper.4. Funnelthepowderintothecup.Youmightwanttosavesomeforlaterincaseyou’dliketoexperiment

withdifferentsolvents.Youcanusebabyoil,water,oralcoholtomixthefluidwith.Theexperimentinthevideousesoil.


5. Addalittlebabyoiltothecupandstirwithapopsiclestick.6. Bringamagnettotheoutsideofthecupandwatchthemagneticliquidsticktothesideofthecup!7. Don’tgetthemagnetabovetherimofthecup,ortheferrofluidwillsticktothemagnetandyou’llneverget

itoffagain.8. Playwiththeferrofluid:

a. Youcanthickenitupbyaddingmorepowdertothemix.Thiswillformamagneticputtyyoucanplaywithaslongasyouhaveglovesonyourhands.Ifyouleaveitonthetableclosetoamagnet,itwillslowlycreeptowardthemagnet.Addatinybitmoreliquidifitdoesn’tappeartomoveoverthecourseof10‐20minutes.

b. Thinitoutwithmoreoiltomakeitmorelikethecommerciallyavailableferrofluid.You’llgetmorespikes,especiallyifyouletitsitforacoupleofhourstocompletelyimmerseintheoil.

c. Bringamagnetclosebutnottouchingthecup.Whathappens?d. Makealargermagneticsurfacefortheferrofluidtointeractwith:

i. Place1‐2strongmagnets(neodymiumworkbest)underyourplasticcup.Ifit’snotstable,addalargewashertothebottomofthemagnetstomakeastand.

ii. Threadanutontoaboltafewturns(notalltheway–leaveitnearthebase)anduprightinthecupsothattheboltisstandinguponitsown.Themagnetswillkeepitstable.

iii. Usingamedicinedropper,slowlydriptheferrofluidontothetopofthebolt.Ifyoupourittooquickly,thefluidwillsplatterandbeverymessytoworkwith.Makesureyourferrofluidisrelativelythinforthisprocess.Youcanusetheferrofluidyoucreatedorthestufffromastore.

iv. Bringamagnetclose(notcloseenoughforittojumpontothebolt,oryou’llmakeahugemess)andobservewhathappens.Whatisthefurthestyoucanmovethemagnetandstillinfluencetheferrofluid?

v. Whathappensifyoutryadifferentmagnet?

Exercises

1. Istheferrofluidasolidoraliquid?(Both,dependingontheconditionsit’splacedin.)2. Doesthestrengthofamagnetmatter?(Yes.Thestrongerthemagnet,themoretheferrofluidinteracts

withthemagnet.)3. Whatwouldhappenifthemagnetwentovertherimofthecup?(Don’tgetthemagnetabovetherimofthe

cup,ortheferrofluidwillsticktothemagnetandyou’llnevergetitoffagain.)4. Doestheferrofluidhaveanorthandsouthpole?(Ferrofluidismadeupofverytinyparticlesmixedwith

water.Theseparticlesdon’t“settleout”butratherremainsuspendedinthefluid.Eachtinyparticlehasanorthandsouthpole.)

5. Whathappensifyoubringacompassneartheferrofluid?(Nothing,untilyoubringamagnetcloseby.Butferrofluidcanconceivablybeusedasacompass.)



Lesson#12:FerrofluidStudentWorksheet

Name______________________________________________________________________

Overview:Todayyougettowatchyourteacherdoalltheworkandmakeamess.We’regoingtolearnaboutliquidmagnets,alsoknownasferrofluids.Ferrofluidsarewhatscientistscall“colloidalsuspensions,”whichmeansthatthesubstancehaspropertiesofbothsolidmetalandliquidwater(oroil),anditcanchangephaseeasilybetweenthetwo.

LabTime

1. Yourteacherisgoingtodemonstratethislabforyou,sinceitmakesanabsolutemessandrequiresdelicatehandlingofsuper‐strongmagnets.Yougettowatchandenjoytheshow,andanswerthequestionsbelow.


1. Istheferrofluidasolidoraliquid?

2. Doesthestrengthofamagnetmatter?

3. Whatwouldhappenifthemagnetwentovertherimofthecup?

4. Doestheferrofluidhaveanorthandsouthpole?

5. Whathappensifyoubringacompassneartheferrofluid?

6. Namethreespecificwaysferrofluidmakesourliveseasier.Howmightyouuseaferrofluidifyouwereinventingsomething?


Lesson#13:BrakingMagnetsTeacherSection

ThisisaBonusLab,meaningthatit’sinadditiontotheexperimentsthekidsgettodothroughoutthecourse.Feelfreetoskipthislabifthematerialsareoutofyourbudget,orsaveitasatreatfortheendoftheyear.Youcanalsojustmakeoneanduseitasademojustforyou.

Overview:Eddycurrentsdefygravityandletyoufloatamagnetinmidair.Thinkofeddycurrentsasbrakesformagnets.Rollercoastersusethemtoslowdownfast‐movingcarsontracksandinfree‐fallelevator‐typerides.Thisisagreatintroductiontothenextsegment,whichisallabouthowelectricityandmagnetismarelinkedtogether.


ObjectivesKidswillmeasure,calculate,andbeamazedathowmagnetismandelectricityworktogether.


Aluminumblock(thethickerthebetter) Neodymiummagnets(getdifferentsizesand/orshapesforeachlabgroupsotheycanswapand

compare) Ruler Stopwatchorclockwithasecondhand

LabPreparation

1. Printoutcopiesofthestudentworksheets.2. Watchthevideoforthisexperimenttoprepareforteachingthisclass.3. Inadditiontothematerialsforthestudents,bringinafewdifferentsheets,includingsteel,plastic,and

woodtoshowthekidsduringthedemonstrationofthelab.Ibringmyplasticandwoodcuttingboardsfromhomeandasteelcookiesheet(it’sgoingtobealotheavierthanaluminum).

4. ReadovertheBackgroundLessonReadingbeforeteachingthisclass.


Whenamagnetmovesnearanobjectthatconductselectricity(likemetal),itcreateselectriccurrentsinthemetal.Thesearecallededdycurrentsandtheystarttoflowinthemetal.Theseeddycurrentsalsocreatemagneticfields(We’regoingtolearnhowelectricitycausesmagnetismverysoon!)intheoppositedirectionofthemovingmagnet,slowinganobjectdownsoitappearstofloatdowntherampslowly.Eddycurrentsarebrakesformovingmagnets.


Lesson

1. Waveyourhandsintheairandtellthekidsyouhavesomesuper‐special,magicmagnetsthatyouwanttoshowthem.

2. Holdupasetofyourstrongestmagnets(andyourlargest,sinceyou’redoingademonstration),andsayacoupleofmagicwordsasyouwiggleyourfingersatthem.Thenlookatthestudentsandtellthemyou’vejustdemagnetizedthem.

3. Makearampfromaplasticsheet(likeacuttingboard)andstartthematthetop.Askthekidstotimehowlongittakesforthemtoreachthebottom.

4. Atthispoint,yourloudeststudentswillprotestand(hopefully)tellyouthatmagnetsdon’tinteractwithplastic.Lookslightlyconcerned,andthenwiggleyourfingersagainatthemagnetswithanothermagicword.Tellthemyou’veaskedthemagnetstonotbemagnetsforaminuteasyouslidethemdownthewoodrampandhavethekidstimethemagnetsagain.

5. Nowthekidsareprobablyallprotestingthatwooddoesn’tworkwithmagnetseither.Perfect.Youhavethemrightwhereyouwantthem.

6. Nowusethesteelcookiesheetasaramp.Putthematthetop,askthekidstotimehowlongittakestoreachthebottom,andreleasethemagnets.Themagnetsshouldstick.Imakeabigshowofstaringatthemagnets,willingthemtomove,takingthecookiesheetandturningitverticalandevenupsidedown,shakingit.Italwaysmakesthemlaughhysterically.

7. Yourstudentsshouldbeshoutingbynow,standingupandwonderingwhatyouateforbreakfastthatmakesyouactsoweirdthismorning.Don’tworry–you’reabouttoplayyourfinalcard.

8. Shrugyourshouldersandsaysomethingaboutforgettingtosaythemagicwordsasyouputawaythesteelsheet(grabthemagnetsoffitfirst).

9. Don’ttellthemthatthelastsheetisaluminum.Justplaceitonthedeskasaramp,wiggleyourfingers,saythelastmagicwordstothemagnets,andstartthemagnetsatthetopofthesheetasthekidspromisetotimeit.Themagnetsmoveslowlydown.

10. Youshouldgetacoupleofgasps.Askforthetimeandcompareitwiththepreviousrecordedtimesfornon‐magnetizedrampsatthesameangle.(We’reignoringtheeffectsoffrictionforthemoment.)

11. Whileyou’reonaroll,takeanon‐magnetizedobject,likeanailorpencilandslideitdowntoshowthatthesurfaceisn’tsticky.Grabthemagnetsandslidethemdownagain.Takethemagnetsandstickthemtothesideofafilecabinetorsomethingmetalnearbytoshowit’snotbecausetheyareweakmagnets(whichtheyaren’t,ifthey’dpaidattentiontothesteelsheetanticsyouperformed.)

12. Slidethemagnetsdownonemoretimeandaskforideasaboutwhat’shappening.Theclassshouldbequietlythinking.

13. Nowisthetimetostartthelab.

LabTime


2. Liftuponeendofthemetalsheet.3. Placeyourmagnetsatthetopoftherampandletgo.Whathappened?Writeithere:4. Completethetable.


Exercises

1. Whatistheaveragespeedofyourfastestmagnet?(Findtheshortesttimeinyourdatatable.Dividethelengthoftherampbythetimeinsecondstogetyouranswerininchespersecond.)

2. Whatmakesthemagnetslowdownthemost?Isitthesizeofthemagnet,thestrengthofmagnet,numberofmagnets,orsomethingelse?(Thestrongerthemagneticfield,themoreeddycurrentsitwillproduceandthemorebrakingthemagnetwillexperience.)

3. Whatifyoustacktwoaluminumplatesontopofeachotherandusethisforaramp?Howwouldthisaffectyourdata?(Thisisgoingtodependonthethicknessofeachplatetobeginwith,butingeneralyou’llgetaslower‐movingmagnetdowntheramp.)

4. Doestheangleoftherampmatter?(Yes,butit’snotobvioustothenakedeyewithouttakingactualmeasurementsbecausethedifferenceissosmall.)



Lesson#13:BrakingMagnetsStudentWorksheet

Name______________________________________________________________________

Overview:Todayyougettomeasure,calculate,andbeamazedathowmagnetismandelectricityworktogether.

WhattoLearnEddycurrentsdefygravityandletyoufloatamagnetinmidair.Thinkofeddycurrentsasbrakesformagnets.Rollercoastersusethemtoslowdownfast‐movingcarsontracksandinfree‐fallelevator‐typerides.Thisisagreatintroductiontothenextsegment,whichisallabouthowelectricityandmagnetismarelinkedtogether.

Materials

Aluminumblock(thethickerthebetter) Neodymiummagnets(getdifferentsizesand/orshapesforeachlabgroupsotheycanswapand

compare) Ruler Stopwatchorclockwithasecondhand

LabTime

1. Liftuponeendofthemetalsheet.2. Placeyourmagnetsatthetopoftherampandletgo.3. Whathappened?Writeithere:

____________________________________________________________________________________________________________

____________________________________________________________________________________________________________

____________________________________________________________________________________________________________

4. Trademagnetswithanotherlabgroupthat’sreadytoswapandredotheexperimentasyoucompletethetableonthenextpage.


BrakingMagnetsDataTable

LengthofRamp:______________________(units?) HeightofRampatStart:____________________________(units?)

ExampleforwhattoputintheNumberof/Size/ShapeofMagnetcolumn:Ifyourexperimentusedtwomagnetsthateachwere½”indiameter(useyourrulertomeasure!),thenwrite:‘2round½”magnets’

Trial# Number/Shape/SizeofMagnet TimetoReachtheBottomofRamp(seconds)

1

2

3

4

5

6

7



1. Whatistheaveragespeedofyourfastestmagnet?

2. Whatmakesthemagnetslowdownthemost?Isitthesizeofthemagnet,thestrengthofthemagnet,numberofmagnets,orsomethingelse?

3. Whatifyoustacktwoaluminumplatesontopofeachotherandusethisforaramp?Howwouldthisaffectyourdata?

4. Doestheangleoftherampmatter?


MagnetsEvaluationTeacherSection

OverviewKidswilldemonstratehowwelltheyunderstandimportantkeyconceptsfromthissection.


ObjectivesStudentswillbetestedonthekeyconceptsofmagnetism:

1. Allmagnetshavetwopoles.Magnetsarecalleddipolar,whichmeanstheyhavetwopoles.Thetwopolesofamagnetarecallednorthandsouthpoles.Themagneticfieldcomesfromanorthpoleandgoestoasouthpole.Oppositepoleswillattractoneanother.Likepoleswillrepeloneanother.

2. Amagneticfieldisanareaaroundamagnetthatwillcreateaforceonanothermagnetthatcomeswithin

reachofthemagneticfield.Infields,theclosersomethinggetstothesourceofthefield,thestrongertheforceofthefieldgets.Thisiscalledtheinversesquarelaw.

3. TheEarthhasahugemagneticfield.TheEarthhasaweakmagneticforce.ThemagneticfieldcomesfromthemovingelectronsinthecurrentsoftheEarth’smoltencore.TheEarthhasanorthandasouthmagneticpolewhichisdifferentfromthegeographicnorthandsouthpole.

4. Compassesturnwiththeforceofthemagneticfield.

5. Ironandafewothertypesofatomswillturntoalignthemselveswiththemagneticfield.

Studentswillalsodemonstratetheseprinciples:

6. Designandbuildasimplecompassanduseittodetectmagneticeffects,includingEarth'smagneticfield.7. Designandbuildexperimentsthatdemonstratetheprinciplesabove.8. Knowhowtodemonstratethatmagnetsattractorrepeleachother.

Materials(onesetforentireclass)

Needle Foam 2differentkindsofmagnets(roundorsquare,N‐Spolelocationsdifferent,etc.) Cupofwater Paperclip Penny Quarter

LabPreparation

1. Printoutcopiesofthestudentworksheets,labpractical,andquiz.2. Haveatubofthematerialsinfrontofyouatyourdesk.Kidswillcomeupwhencalledanddemonstrate

theirknowledgeusingthesematerials.


Lesson

Thestudentsaretakingtwoteststoday:thequizandthelabpractical.Thequiztakesabout20minutes,andyou’llfindtheanswerkeytomakeiteasytograde.

LabPractical

Studentswilldemonstrateindividuallythattheyknowmagneticobjectsattractorrepeleachother.Whileotherkidsarewaitingfortheirturn,theyhaveachoiceofthreedifferenthomeworkassignmentstogetstartedon.Youchoosewhethertheygettoworktogetherorindividually.


MagnetsEvaluation

StudentWorksheet

Overview:Todayyou’regoingtotaketwodifferenttests:thequizandthelabpractical.You’regoingtotakethewrittenquizfirst,andthelabpracticalattheendofthistest.Thelabpracticalisn’tapapertest–it’swhereyougettoshowyourteacherthatyouknowhowtodosomething.

LabTest&Homework

1. Yourteacherwillcallyouupsoyoucansharehowmuchyouunderstandaboutmagnetsandhowtheyinteractwitheachother.Sincescienceissomuchmorethanjustreadingabookorcirclingtherightanswer,thisisanimportantpartofthetesttofindoutwhatyoureallyunderstand.

2. Whileyouarewaitingforyourturntoshowyourteacherhowmuchofthisstuffyoualreadyknow,yougettochoosewhichhomeworkassignmentyouwanttocomplete.Theassignmentisduetomorrow,andhalfthecreditisforcreativityandtheotherhalfisforcontent,soreallyletyourimaginationflyasyouworkthroughit.Chooseone:a. Writeashortstoryorskitaboutmagnetismfromtheperspectiveoftheelectronorthemagnetitself.

You’llreadthisaloudtoyourclass.b. Makeaposterthatteachesthemainconceptstomagnetism.Whenyou’refinished,you’lluseitto

teachaclassintheyoungergradesanddemonstrateeachoftheprinciplesthatyou’velearned.c. Writeandperformapoemorsongaboutmagnetism.Thiswillbeperformedtoyourclass.


MagnetsQuizTeacher’sAnswerKey

1. Howmanypolesdomagnetshave,andwhatarethey?Two.Northandsouthpoles.2. Whathappenswhenyoubringtwolikepolestogether?Theyrepeleachother.3. HowdoIknowwhichpoleiswhichonamagnet?Puttwomagnetstogetherandfindthespotwheretheyare

repellingthestrongest.Thepolesfacingeachotherarethesame.Orbringitclosetoacompass.Ifthemagnetattractstheneedletonorth,thenthemagnet’spoleisthesouthpole.

4. Isthemagneticforcestrongerorweakerthecloseramagnetgetstoanothermagnet?Stronger.5. Whatkindsofmaterialsaremagnetsmadefrom?Iron,nickelandcobalt.6. Namethreeobjectsthatsticktoamagnet.Paperclips,pipecleaners,andstaples.7. Namethreethatdon’tsticktoamagnet.USquarter,glass,plastic.8. Whatdoesacompassdetect?Howdoyouknowwhenit’sdetectedit?Thedirectionofamagneticfield.

Whentheneedleisdeflected,thecompassisinamagneticfield.9. Circlethecorrectanswerintheparenthesis:

a.TheEarthhasa(tiny|huge)magneticfield.

b.TheEarthhasa(strong|weak)magneticforce.

c.ThemagneticfieldcomesfromthemovingelectronsinthecurrentsoftheEarth’s(moltencore|rockycore).

d.TheEarthhasanorthandasouthmagneticpolewhichis(thesame|different)fromthegeographicnorthandsouthpole.


MagnetsQuiz

Name__________________________________________________________

1. Howmanypolesdomagnetshave,andwhatarethey?

2. Whathappenswhenyoubringtwolikepolestogether?

3. HowdoIknowwhichpoleiswhichonamagnet?

4. Isthemagneticforcestrongerorweakerthecloseramagnetgetstoanothermagnet?

5. Whatkindsofmaterialsaremagnetsmadefrom?


6. Namethreeobjectsthatsticktoamagnet.

7. Namethreethatdon’tsticktoamagnet.

8. Whatdoesacompassdetect?Howdoyouknowwhenit’sdetectedit?

9. Circlethecorrectanswerintheparenthesis:

a.TheEarthhasa(tiny|huge)magneticfield.

b.TheEarthhasa(strong|weak)magneticforce.

c.ThemagneticfieldcomesfromthemovingelectronsinthecurrentsoftheEarth’s(moltencore|rockycore).

d.TheEarthhasanorthandasouthmagneticpolewhichis(thesame|different)fromthegeographicnorthandsouthpole.


MagnetsLabPracticalTeacher’sAnswerKey

Thisisyourchancetoseehowwellyourstudentshavepickeduponimportantkeyconcepts,andifthereareanyholes.Yourstudentsalsowillbeworkingontheirhomeworkassignmentasyoudothistestindividuallywiththestudents.

Materials:

Needle Foam 2differentkindsofmagnets(roundorsquare,N‐Spolelocationsdifferent,etc.) Cupofwater Paperclip Penny Quarter

LabPractical:AskthestudentNote:Answersgiveninitalics!

Designandbuildanexperimentthatshowshowtodetectamagneticfield.Magnetizetheneedlebywipingitinonedirectionwithamagnet,stickitthroughapieceoffoam,andfloatitinacupofwater.Comparethereadingwithyourownhiddencompass.Studentcanalsobringamagnetcloseandtheneedledeflects.

Usingallthematerials,eventhecupandthefoam(removetheneedle),separatetheobjectsintotwopiles:onepileforthingsthatarenotmagneticallyattractedandanotherthataremagneticallyattracted.Whenthestudentfinishes,runamagnetoverthetwopilesandseeiftheobjectsareinthecorrectpiles.


ELECTROMAGNETISM

Oneofthefourfundamentalforcesofnature,theelectromagneticforceistheonethatbindsatomstogether,allowsyoutowalkdownthestreet,andissolelyresponsibleforbadhairdaysworldwide.Oneofthegreatestleapsinsciencewasthediscoverythattheelectricityandmagnetismwereapartofeachother,andnotseparate.

Bythetimeyou’rethroughwiththislesson,you’llhavecreatedparticleaccelerators,galvanometers,uni‐polarmotors,listenedtoamagnet(nokidding!),andbuiltaworkingDCmotor.Thisvideowillgetyoustartedontherightfootforyourstudyintoelectromagnetism.


Lesson#14:GalvanometersTeacherSection

OverviewGalvanometersarecoilsofwireconnectedtoabattery.Whencurrentflowsthroughthewire,itcreatesamagneticfield.Sincethewireisbundledup,itmultipliesthiselectromagneticeffecttocreateasimpleelectromagnetthatyoucandetectwithyourcompass.


ObjectivesKidswillbegintodiscoverhowelectricityandmagnetismcauseeachother.Inthesecondhalfofthislab,they’llgettodooneofthemostimportantscientificdiscoveriesofalltime:howmagnetismcauseselectricity.


Magnetwire Sandpaper Scissors Compass AAbatterycase 2AAbatteries 2alligatorclipwires Strongmagnet Toiletpaperorpapertoweltube

LabPreparation

1. Printoutcopiesofthestudentworksheets.2. Watchthevideoforthisexperimenttoprepareforteachingthisclass.3. ReadovertheBackgroundLessonReadingbeforeteachingthisclass.4. Precutthewireandwinditontoasecondtoiletpapertube(you’llneedanotherfortheexperimentitself)

soitdoesn’tgetalltwistedup.Iusuallygetasetofspoolsandputoneineachbin,sincewe’regoingtousealotofmagnetwireforourexperimentsinthissection.

5. Precutthesandpaperinto2”squares.You’llbeusingthisforseveralexperiments.


Nowwe’vecoveredthefactthatmagneticfieldsarecausedbyelectronsmovinginthesamedirection.Uptothispoint,we’vebeenfocusingonmagnetismbeingcausedbyanunequalnumberofelectronsspinninginthesamedirectioninanatom.

Ifanatomhasmoreelectronsspinninginonedirectionthanintheotherdirection,thatatomwillhaveamagneticfield.Whenbunchesoftheseatomsgettogether,wehaveapermanentmagnet.Nowwe’regoingtotalkaboutwhathappensifweforceelectronstomove.

Thisisoneofthemostimportantscientificdiscoveriesofalltime.Onestoryaboutthisdiscoverygoeslikethis:


Ascienceteacherdoingademonstrationforhisstudents(CanyouseewhyIlikethisstory?)noticedthatashemovedamagnet,hecausedoneofhisinstrumentstoregistertheflowofelectricity.Heexperimentedabitfurtherwiththisandnoticedthatamovingmagneticfieldcanactuallycreateelectricalcurrent,thustyingthemagnetismandtheelectricitytogether.

Beforethat,theywereseenastwocompletelydifferentphenomena!Nowweknowthatyoucan’thaveanelectricfieldwithoutamagneticfield.Youalsocannothaveamovingmagneticfieldwithoutcausingelectricityinobjectsthatelectronscanmovein(likewires).Movingelectronscreateamagneticfieldandmovingmagneticfieldscancreateelectriccurrents.

“So,ifIjustmadeelectricity,canIpoweralightbulbbymovingamagnetaround?”

Yes,ifyoumovedthatmagnetbackandforthfastenoughyoucouldpoweralightbulb.However,byfastenough,Imeanlike1000timesasecondormore!Ifyouhadastrongermagnet,ormanymorecoilsinyourwire,thenyoucouldmakeagreateramountofelectricityeachtimeyoumovedthemagnetthroughthewire.

Believeitornot,mostoftheelectricityyouusecomesfrommovingmagnetsaroundcoilsofwire!ElectricalpowerplantseitherspinHUGEcoilsofwirearoundverypowerfulmagnetsortheyspinverypowerfulmagnetsaroundHUGEcoilsofwire.Theelectricitytopoweryourcomputer,yourlights,yourairconditioning,yourradioorwhatever,comesfromspinningmagnetsorwires!

“But,whataboutallthosenuclearandcoalpowerplantsIhearaboutallthetime?”

Goodquestion.Doyouknowwhatthatnuclearandcoalstuffdoes?Itgetsreallyhot.Whenitgetsreallyhot,itboilswater.Whenitboilswater,itmakessteamanddoyouknowwhatthesteamdoes?Itcausesgiantwheelstoturn.Guesswhat’sonthosegiantwheels.That’sright,ahugecoilofwireorverypowerfulmagnets!

Coalandnuclearenergybasicallydolittlemorethanboilwater.Withtheexceptionofsolarenergyalmostallelectricalproductioncomesfromsomethinghugespinningreallyfast!

LabTime


1. Wrapthewireatleast30‐50timesaroundyourfingers,makingsureyourcoilislargeenoughtoslidethecompassthrough.Takeoneoftheendsofthewireandwrapitacoupleoftimesaroundasectionofthecircletokeepthewirefromunwinding.Dothisforbothsides.

2. Removetheinsulationfromaboutaninchofeachendofthemagnetwireusingsandpaper.3. Connectoneendofthewiretothebatterycasewire.4. Whilelookingatthecompass,repeatedlytaptheotherendofthewireonthebattery.Youshouldseethe

compassreacttothetapping.6. Switchthewiresfromoneterminalofthebatterytotheother.Nowtapagain.Doyouseeadifferenceinthe

waythecompassmoves?7. Youjustmadeasimplegalvanometer.“Ohboy,that’sgreat!HeyBob,takealook!Ijustmadea….awhat?!?”I

thoughtyoumightaskthatquestion.Agalvanometerisadevicethatisusedtofindandmeasureelectriccurrent.“But,itmadeacompassneedlemove…isn’tthatamagneticfield,notelectricity?”Ah,yes,butholdonaminute.Whatiselectriccurrent…movingelectrons.Whatdomovingelectronscreate…amagneticfield!Bythegalvanometerdetectingachangeinthemagneticfield,itisactuallymeasuringelectricalcurrent!So,nowthatyou’vemadeone,let’suseit!


8. Takeyournewpieceofwireandwrapthiswiretightlyandcarefullyaroundtheendofthepapertoweltube.Doasmanywrapsasyoucanwhilestillleavingabout4inchesofwireonbothsidesofthecoil.Youmaywanttoputapieceoftapeonthecoiltokeepitfromunwinding.Pullthecoilfromthepapertoweltube,keepingthecoiltightlywrapped.Takeoneoftheendsofthewireandwrapitacoupleoftimesaroundasectionofthecircletokeepthewirefromunwinding.Dothisforbothsides.

9. Removeaboutaninchofinsulationfrombothendsofthewireusingsandpaper.10. Hookupyournewcoilwithyourgalvanometer.Onewireofthecoilshouldbeconnectedtoonewireofthe

galvanometerandtheotherwireshouldbeconnectedtotheotherendofthegalvanometer.11. Nowmoveyourmagnetinandoutofthecoil.Canyouseethecompassmove?Doesastrongerorweaker

magnetmakethecompassmovemore?Doesitmatterhowfastyoumovethemagnetinandoutofthecoil?12. TaaDaa!!!Ladiesandgentlemen,youjustmadeelectricity!!!!!Youalsojustre‐createdoneofthemost

importantscientificdiscoveriesofalltime.Onestoryaboutthisdiscoverygoeslikethis:Ascienceteacherdoingademonstrationforhisstudents(CanyouseewhyIlikethisstory?)noticedthatashemovedamagnet,hecausedoneofhisinstrumentstoregistertheflowofelectricity.Heexperimentedabitfurtherwiththisandnoticedthatamovingmagneticfieldcanactuallycreateelectricalcurrent,thustyingthemagnetismandtheelectricitytogether.Beforethat,theywereseenastwocompletelydifferentphenomena!

13. Now,weknowthatyoucan’thaveanelectricfieldwithoutamagneticfield.Youalsocannothaveamovingmagneticfieldwithoutcausingelectricityinobjectsthatelectronscanmovein(likewires).Movingelectronscreateamagneticfieldandmovingmagneticfieldscancreateelectriccurrents.

14. “So,ifIjustmadeelectricity,canIpoweralightbulbbymovingamagnetaround?”Yes,ifyoumovedthatmagnetbackandforthfastenoughyoucouldpoweralightbulb.However,byfastenough,Imeanlike1,000timesasecondormore!Ifyouhadastrongermagnet,ormanymorecoilsinyourwire,thenyoucouldmakeagreateramountofelectricityeachtimeyoumovedthemagnetthroughthewire.

15. Believeitornot,mostoftheelectricityyouusecomesfrommovingmagnetsaroundcoilsofwire!ElectricalpowerplantseitherspinHUGEcoilsofwirearoundverypowerfulmagnetsortheyspinverypowerfulmagnetsaroundHUGEcoilsofwire.Theelectricitytopoweryourcomputer,yourlights,yourairconditioning,yourradioorwhatever,comesfromspinningmagnetsorwires!

16. “ButwhataboutallthosenuclearandcoalpowerplantsIhearaboutallthetime?”Goodquestion.Doyouknowwhatthatnuclearandcoalstuffdoes?Itgetsreallyhot.Whenitgetsreallyhot,itboilswater.Whenitboilswater,itmakessteamanddoyouknowwhatthesteamdoes?Itcausesgiantwheelstoturn.Guesswhat’sonthosegiantwheels.That’sright,ahugecoilofwireorverypowerfulmagnets!Coalandnuclearenergybasicallydolittlemorethanboilwater.Withtheexceptionofsolarenergy,almostallelectricalproductioncomesfromsomethinghugespinningreallyfast!

Exercises

1. Whydidn’tthecoilofwireworkwhenitwasn’thookeduptoabattery?Whatdoesthebatterydotothecoilofwire?(Thewireisjustwireuntilyouhaveelectricitypassingthroughit.Theelectricitycausesasmallmagneticfieldaroundthewire.Whenyoubundleandcoilthewireup,youmultiplythiseffecttocreateanelectromagnet.)

2. Howdoesamovingmagnetmakeelectricity?(Ifyoumovedthatmagnetbackandforthalongacoilofwirefastenoughyoucouldpoweralightbulb.However,byfastenough,Imeanlike1,000timesasecondormore!)


3. Whatmakesthecompassneedledeflectinthesecondcoil?(Whenamagnetismovedinandoutofthefirstcoilquickly,itcreatesacurrentinthewirewhichtravelstothesecondcoilofwire,turningthesecondoneintoanelectromagnet.Anelectromagnetisamagnetthatyoucanturnonandoffwithelectricity.Sincethecompassisaffectedbymagnets,thistellsusthatthecompassisnearamagneticfieldwhenitdeflects,whichmeansthatthewireiscreatingamagneticfield.)

4. Doesastrongerorweakermagnetmakethecompassmovemore?(Stronger)5. Doesitmatterhowfastyoumovethemagnetinandoutofthecoil?(Yes–thefasteryoumoveit,themore

theneedledeflects.)



Lesson#14:GalvanometersStudentWorksheet

Name______________________________________________________________________

OverviewTodayisaveryimportantdayinyourmagnetismstudies.Youwillbegintodiscoverhowelectricityandmagnetismcauseeachother.Inthesecondhalfofthislab,they’llgettore‐enactoneofthemostimportantscientificdiscoveriesofalltime:howmagnetismcauseselectricity.

WhattoLearnGalvanometersarecoilsofwireconnectedtoabattery.Whencurrentflowsthroughthewire,itcreatesamagneticfield.Sincethewireisbundledup,itmultipliesthiselectromagneticeffecttocreateasimpleelectromagnetthatyoucandetectwithyourcompass.

Materials

Magnetwire Sandpaper Scissors Compass AAbatterycase 2AAbatteries 2alligatorclipwires Strongmagnet Toiletpaperorpapertoweltube

LabTime

1. Wrapthewire30‐50timesaroundyourfingers,makingsureyourcoilislargeenoughtoslidethecompassthrough.Takeoneoftheendsofthewireandwrapitacoupleoftimesaroundasectionofthecircletokeepthewirefromunwinding.Dothisforbothsides.

2. Removetheinsulationfromaboutaninchofeachendofthewire.Usesandpaperifyou’reusingmagnetwire.

3. Connectoneendofthewiretothebatterycasewire.4. Whilelookingatthecompass,repeatedlytaptheotherendofthewiretothebattery.Youshouldseethe

compassreacttothetapping.5. Switchthewiresfromoneterminalofthebatterytotheother.Nowtapagain.Doyouseeadifferenceinthe

waythecompassmoves?Writeithere:_________________________________________________________________________________________________________________

6. Youjustmadeasimplegalvanometer.“Ohboy,that’sgreat!HeyBob,takealook!Ijustmadea….awhat?!?”Ithoughtyoumightaskthatquestion.Agalvanometerisadevicethatisusedtofindandmeasureelectriccurrent.“But,itmadeacompassneedlemove…isn’tthatamagneticfield,notelectricity?”Ah,yes,butholdon


aminute.Whatiselectriccurrent…movingelectrons.Whatdomovingelectronscreate…amagneticfield!Bythegalvanometerdetectingachangeinthemagneticfield,itisactuallymeasuringelectricalcurrent!So,nowthatyou’vemadeonelet’suseit!

7. Takeyournewpieceofwireandwrapthiswiretightlyandcarefullyaroundtheendofthepapertoweltube.Doasmanywrapsasyoucanwhilestillleavingabout4inchesofwireonbothsidesofthecoil.Youmaywanttoputapieceoftapeonthecoiltokeepitfromunwinding.Pullthecoilfromthepapertoweltube,keepingthecoiltightlywrapped.Takeoneoftheendsofthewireandwrapitacoupleoftimesaroundasectionofthecircletokeepthewirefromunwinding.Dothisforbothsides.

8. Removeaboutaninchofinsulationfrombothendsofthewireusingsandpaper.9. Hookupyournewcoilwithyourgalvanometer.Onewireofthecoilshouldbeconnectedtoonewireofthe

galvanometerandtheotherwireshouldbeconnectedtotheotherendofthegalvanometer.10. Nowmoveyourmagnetinandoutofthecoil.Canyouseethecompassmove?Doesastrongerorweaker

magnetmakethecompassmovemore?Doesitmatterhowfastyoumovethemagnetinandoutofthecoil?11. TaaDaa!!!Ladiesandgentlemenyoujustmadeelectricity!!!!!Youalsojustre‐createdoneofthemost

importantscientificdiscoveriesofalltime.12. Now,weknowthatyoucan’thaveanelectricfieldwithoutamagneticfield.Youalsocannothaveamoving

magneticfieldwithoutcausingelectricityinobjectsthatelectronscanmovein(likewires).Movingelectronscreateamagneticfield,andmovingmagneticfieldscancreateelectriccurrents.

13. “So,ifIjustmadeelectricity,canIpoweralightbulbbymovingamagnetaround?”Yes,ifyoumovedthatmagnetbackandforthfastenoughyoucouldpoweralightbulb.However,byfastenough,Imeanlike1,000timesasecondormore!Ifyouhadastrongermagnet,ormanymorecoilsinyourwire,thenyoucouldmakeagreateramountofelectricityeachtimeyoumovedthemagnetthroughthewire.

14. Believeitornot,mostoftheelectricityyouusecomesfrommovingmagnetsaroundcoilsofwire!ElectricalpowerplantseitherspinHUGEcoilsofwirearoundverypowerfulmagnetsortheyspinverypowerfulmagnetsaroundHUGEcoilsofwire.Theelectricitytopoweryourcomputer,yourlights,yourairconditioning,yourradioorwhatever,comesfromspinningmagnetsorwires!

15. “ButwhataboutallthosenuclearandcoalpowerplantsIhearaboutallthetime?”Goodquestion.Doyouknowwhatthatnuclearandcoalstuffdoes?Itgetsreallyhot.Whenitgetsreallyhot,itboilswater.Whenitboilswater,itmakessteamanddoyouknowwhatthesteamdoes?Itcausesgiantwheelstoturn.Guesswhat’sonthosegiantwheels.That’sright,ahugecoilofwireorverypowerfulmagnets!Coalandnuclearenergybasicallydolittlemorethanboilwater.Withtheexceptionofsolarenergyalmostallelectricalproductioncomesfromsomethinghugespinningreallyfast!

16. Drawoutyourexperiment,showinghowthemagnetcreateselectricityandwhere/howthatelectricitycreatesmagnetism.Labelallthedifferentpartsofyourexperiment:


ExercisesAnswerthequestionsbelow:1. Whydidn’tthecoilofwireworkwhenitwasn’thookeduptoabattery?Whatdoesthebatterydotothe

coilofwire?

2. Howdoesamovingmagnetmakeelectricity?

3. Whatmakesthecompassneedledeflectinthesecondcoil?

4. Doesastrongerorweakermagnetmakethecompassmovemore?

5. Doesitmatterhowfastyoumovethemagnetinandoutofthecoil?


Lesson#15:ElectromagnetsTeacherSection

OverviewWe’regoingtomakeamagnet(several,actually)thatturnonandoffusingelectricity.Kidswilluseseveraldifferentmaterialsfortheelectromagnetcoreinadditiontofiguringouthowmuchwiretheyneedtocreatethestrongestelectromagnet.


ObjectivesKidswilllearnhowelectriccurrentsproducemagneticfieldsandhowtobuildasimpleelectromagnet.


AAbatterycase 2AAbatteries 2alligatorclipwires 5nails(2‐3”long,rust‐free) Magnetwire Paperclips Pencil Chopstick Straw Plasticfork Rubbereraser Tape Compass

LabPreparation

1. Printoutcopiesofthestudentworksheets.2. Watchthevideoforthisexperimenttoprepareforteachingthisclass.3. ReadovertheBackgroundLessonReadingbeforeteachingthisclass.4. Thevideoshowshowyoucanquicklywrapthemagnetwire.However,thestudentswillbewrappingtheir

ownaspartoftheirdatameasurementsforthefirstpartofthislab.Ifyouwanttoshortenupthelabtime,thenwrapwiresforthemoneachoftheobjectsforthesecondpartofthelab.You’llwanteachlabgrouptohaveaspoolofwiresoitdoesn’tholduptheclasswhentheywrapthenails.


Anelectromagnetisamagnetyoucanturnonandoffusingelectricity.Byhookingupacoilofwireuptoabattery,youwillcreateanelectromagnet.Whenyoudisconnectit,itturnsbackintoacoilofwire.Sincemovingelectronscauseamagneticfield,whenconnectingthetwoendsofyourwireuptothebattery,youcausedtheelectronsinthewiretomovethroughthewireinonedirection.Sincemanyelectronsaremovinginonedirection,yougetamagneticfield!


Thenailhelpstofocusthefieldandstrengthenit.Infact,ifyoucouldseetheatomsinsidethenail,youwouldbeabletoseethemturntoalignthemselveswiththemagneticfieldcreatedbytheelectronsmovingthroughthewire.Youcantestthenailbyitself(withthewireremoved)afteryou’vedonetheexperiment,becauseyoumayhavecausedittobecomeapermanentmagnet.

Lesson

1. Imadeanelectromagnettouseasademonstrationpiece.Ihaveahugefoot‐longnailwrappedwithanentirespoolofmagnetwirethatIhookuptoa4amppowersupply.WhenIswitchiton,itpicksupboxesofpaperclips.AfterIswitchitoff,thenailisstillmagnetized,whichIshowthekidsbydisconnectingthewiresfromthenailandshowingthemhowitstillcanpickupnails.ThenIaskforideasonhowtodemagnetizethenail.TheturningpointquestionIaskis:“Ifelectricitymadeallthedomains(atoms)insidethenaillineupinthesamedirection,thenwhatwillmakethemnotlineup?”ThenItossitonsomethinghard,likethefloor.Pickingitup,Iholditnexttothepileofpaperclipsanditdoesn’tevenpickupone.

2. YoucandotheabovedemonstrationwithanysizenailandaD‐cellbattery,whichisusuallyenoughtogettheirinterestgoingaboutelectromagnets.

LabTime


2. Wrapyourwire20timesaroundthenail.Besuretoalwayswrapinthesamedirection.Ifyoustartwrappingclockwise,forexample,besuretokeepwrappingclockwise.

3. Cliptheendsoff,leaving4”tailsforbothwires.4. Takeyourwireandremoveaboutaninchofinsulationfrombothendsusingsandpaper.5. Now,connectoneendofyourwiretooneterminalofthebatteryusinganalligatorclip.6. Lastly,connecttheotherendofthewiretotheotherterminalofthebatteryusingasecondalligatorclip

leadtoconnecttheelectromagnetwiretothebatterywire.Thisiswherethewiremaybegintoheatup,sobecareful.

7. Moveyourcompassaroundyourelectromagnet.Doesitaffectthecompass?8. Bringyourelectromagnetnexttoapileofpaperclips.Seeifyourelectromagnetcanpickuppaperclips.9. Switchthewiresfromoneterminalofthebatterytotheother.Electricityisnowmovingintheopposite

directionfromthedirectionitwasmovinginbefore.Trythecompassagain.Doyouseeachangeinwhichendofthenailthenorthsideofthecompasspointsto?Writeithere:

______________________________________________________________________________________________________________

10. Repeatsteps2‐5asyoucompletethetable.

Exercises

1. Howdoesthenumberofwrapsaffecttheelectromagnet?(Themoretimesyouwrapthewire,thestrongertheelectromagnetwillbe.)

2. Doesitmatterifyouwrapneatandtight,orlooseandmessy?(Neatandtightcreatesastrongermagneticfield.)


3. Whenyouuncliptheelectromagnetfromthebattery,doesitstillpickuppaperclips?Whyorwhynot?(Ifyou’veleftitconnectedlongenough,you’llgetsomeresidualmagnetisminsidethenail,whichwillmakethenailstillbeamagnetevenafterthepowerisshutoff.Ifnot,thenyoudidn’thaveenoughpowerforlongenoughrunningthroughthewire.)

4. Howdoyoudemagnetizethenail?(Throwitonthefloororhitittojarandjumbleupthedomainsinside.)5. Whyisthisthingcalledanelectromagnetandnotjustamagnet?(Anelectromagnetisamagnetthatcan

beturnedoffandoffusingelectricity.)6. Whichobjectmadethebestelectromagnet?(Nail.)7. Wherespecificallyonthenaildidthepaperclipsgetpickedup?(Ontheends.)



Lesson#15:ElectromagnetsStudentWorksheet

Name______________________________________________________________________

OverviewWe’regoingtomakeamagnet(several,actually)thatturnonandoffusingelectricity.Today,yougettodiscoverhowelectriccurrentsproducemagneticfieldsandhowtobuildasimpleelectromagnet.

WhattoLearnAnelectromagnetisamagnetyoucanturnonandoffusingelectricity.Byhookingupacoilofwireuptoabattery,youwillcreateanelectromagnet.Whenyoudisconnectit,itturnsbackintoacoilofwire.Sincemovingelectronscauseamagneticfield,whenconnectingthetwoendsofyourwireuptothebattery,youcausedtheelectronsinthewiretomovethroughthewireinonedirection.Sincemanyelectronsaremovinginonedirection,yougetamagneticfield!

Materials

AAbatterycase 2AAbatteries 2alligatorclipwires 5nails(2‐3”long,rust‐free) Magnetwire Paperclips Pencil

Chopstick Straw Plasticfork Rubbereraser Tape Compass

LabTime

1. Wrapyourwire20timesaroundthenail.Besuretoalwayswrapinthesamedirection.Ifyoustartwrappingclockwise,forexample,besuretokeepwrappingclockwise.

2. Cliptheendsoff,leaving4”tailsforbothwires.3. Takeyourwireandremoveaboutaninchofinsulationfrombothendsusingsandpaper.4. Now,connectoneendofyourwiretooneterminalofthebatteryusinganalligatorclip.5. Lastly,connecttheotherendofthewiretotheotherterminalofthebatteryusingasecondalligatorclip

leadtoconnecttheelectromagnetwiretothebatterywire.Thisiswherethewiremaybegintoheatup,sobecareful.

6. Moveyourcompassaroundyourelectromagnet.Doesitaffectthecompass?7. Bringyourelectromagnetnexttoapileofpaperclips.Seeifyourelectromagnetcanpickuppaperclips.8. Switchthewiresfromoneterminalofthebatterytotheother.Electricityisnowmovingintheopposite

directionfromthedirectionitwasmovinginbefore.Trythecompassagain.Doyouseeachangeinwhichendofthenailthenorthsideofthecompasspointsto?Writeithere:

______________________________________________________________________________________________________________

9. Repeatsteps2‐5withanewnailforeachasyoucompletethetable.YouwillbemakingfivenailelectromagnetsforDataTable#1.


ElectromagnetDataTable#1

NumberofWrapsAroundtheNail HowManyPaperclipsPickedUp?

20

40

60

80

100

ElectromagnetDataTable#2

Makesureyouwrapthesamenumberofturnsaroundeachobject!Don’tforgettosandtheendsofthewiresbeforeconnectingittoyourbattery.

ObjectUsedtoWrapWireAround40times HowManyPaperclipsPickedUp?

Pencil

Chopstick

Straw

Plasticfork

Rubbereraser

10. Rankeachobjectfrombest(1)electromagnettoworst(6):

____Nailelectromagnet

____Pencilelectromagnet

____Chopstickelectromagnet

____Strawelectromagnet

____Plasticforkelectromagnet

____Rubbereraserelectromagnet

Exercises


1. Howdoesthenumberofwrapsaffecttheelectromagnet?

2. Doesitmatterifyouwrapneatandtight,orlooseandmessy?

3. Whenyouuncliptheelectromagnetfromthebattery,doesitstillpickuppaperclips?Whyorwhynot?

4. Howdoyoudemagnetizethenail?

5. Whyisthisthingcalledanelectromagnetandnotjustamagnet?

6. Whichobjectmadethebestelectromagnet?

7. Wherespecificallyonthenaildidthepaperclipsgetpickedup?


Lesson#16:MotorsandGeneratorsTeacherSection

OverviewInsideyourmotorarepermanentmagnets(redandbluethingsinthephoto)andanelectromagnet(thecopperthingwrappedaroundthemiddle).Normally,you’dhookupabatterytothetwotabs(terminals)atthebackofthemotor,andyourshaftwouldspin.However,ifyouspinthemotorshaftwithyourfingers,you’llgenerateelectricityattheterminals.Buthowisthatpossible?That’swhatthislabexperimentisallabout.


ObjectivesKidswilllearntheroleofelectromagnetsintheconstructionofelectricmotorsandelectricgenerators.


9‐18VDChobbymotor(RadioShackpart#273‐256) Bi‐polarLED(RadioShackpart#276‐012) 2alligatorwires Propeller Hairdryer(havethestudentsbringtheirsfromhome) Optional:DigitalMultimeter(DMM)frompreviousElectricityunit

LabPreparation

1. Printoutcopiesofthestudentworksheets.Ifyoudon’thavetheDMM,thenonlycopydatatable#1.IfyoudohavetheDMM,skipdatatable#1andcopy#2and#3.Theexercisesarewrittenrightafterdatatable#1and#3sothisworksoutformakingcopies.

2. Watchthevideoforthisexperimenttoprepareforteachingthisclass.3. ReadovertheBackgroundLessonReadingbeforeteachingthisclass.4. IfyouhavecompletedthepreviousElectricityunit,thentakeoutyourDMMandwe’lluseitinthelabto

takedatafortables#2and#3.Ifyouhaven’t,justskipthatpartfornowandenjoyplayingwiththemotorsandcompletingdatatable#1.

5. Ifyouhaveanextra,removethebackfromaDCmotor(youcanuseasmaller1.3‐3VDChobbymotor–theyareallthesameinside)soyoucanshowthekidstheelectromagnetandthepermanentmagnetsinside.Keepthisinabaggiesoyoucanreuseityearafteryear.



Ifyoumoveamagnetalongthelengthofawire,itwillcreateaveryfaintbitofelectricityinsidethewire.Ifyoumovedthatmagnetbackandforthfastenoughyoucouldpoweralightbulb.However,byfastenough,Imeanlike1,000timesasecondormore!Ifyouhadastrongermagnet,ormanymorecoilsinyourwire,thenyoucouldmakeagreateramountofelectricityeachtimeyoumovedthemagnetpastthewire.

Amotorhasacoilofwirewrappedaroundacentralaxis,soinsteadofrubbingbackandforth(whichistoughtogetgoingfastenough,becauseyouhavetostop,reversedirection,andstartmovingagaineverysooften),itrotatespastasetofmagnetscontinuously.

Whenyouaddabatterypacktothemotorterminalsattheback,youenergizethecoilinsidethemotor,anditbeginstorotatetoattempttolineupitsnorthandsouthpoles.Butthemagnetsarelinedupinawaythatitwillcontinually‘miss’andovershoot,whichkeepstheshaftspinningoverandover,fasterandfaster.

WhenyouremovethebatteriesfromthemotorandattachanLEDinstead,youtransformthemotorintoagenerator.Whenyouspintheshaftwithyourfingers,youareconvertingrotationenergyintoelectricalenergy,whichisseenwhentheLEDlightsup.Thecoilspinsinside,movingpastasetofmagnets.RememberfromExperiment13:Galvanometersthatwhenyoumoveamagnetpastacoilofwire,itcreateselectricity?That’sexactlywhat’shappeningtolightupyourLEDwhenyouspintheshaft.

Lesson

1. IhaveasmallbikechaineduptoturnalargeDCmotor,whichisalsoattachedtoseveralobjectslikeafan,cartaillight,andbuzzer.Istartmyclassbyaskingforavolunteertopedalthebike.Atfirst,nothingisconnected–themotorisjustturningandthekidissmiling.WhenIfliptheswitchtoengagethefan,thepedalsgetalittlehardertoturnandthestudentstartstoconcentrateonpedaling.WhenIturnonthelights,thepedalsareverydifficulttoturn,sincethelightsdrawsomuchmorepower.Thestudentstrugglestoturnthepedalsnow.Finally,Iflipthebuzzer,whichdoesn’tworkatall…untilthestudentpedalsbackwards.Thisisagreatillustrationaboutpolarityandhowsomeelectricalcomponents(LEDsandbuzzersforexample)arepickyaboutwhichwaytheelectronsflowthroughthem.Iknowthatmostteachersaren’tgoingtohavethiskindofequipmentintheirclassroom,soI’vecreatedasmalldesktopversionyoucandowiththekidsinthislab.

2. Youcanturnyourmotorintoageneratorbysimplygivingtheshaftaquickspinwithyourfingers.Rememberthatattachedtothisshaftisacoilofwire.Whenyouspintheshaft,you’realsomovingacoilofwirepastthepermanentmagnetsinsidethemotor,whichwillcreateelectricityinyourcoilwhichwillflowouttheterminals.We’llbemeasuringthiswithourdigitalmultimeters(ifyou’vecompletedthepreviousElectricityunit).

3. Youcanattachalow‐voltageLEDdirectlytothemotorterminalsandspintheshafttoseetheLEDlightup.Dependingonthesizeofthemagnetsinsideyourmotor,youmayneedtospintheshaftsuperfasttoseetheLEDlightup.Thelargerthemotor,theeasierthisactivityis.

4. Dragthemotorthroughapileofpaperclips–youshouldgetacoupletostick.Askthekidswhattheythinkisinsidethemotor.Ifyou’vetakenapartanoldone,nowisthetimetobringitoutandshowthekidstheelectromagnetandpermanentmagnetsinside.

LabTime



2. Takeyourmotorandopenupthetabsontheend(iftheyaredown).3. InsertonelegoftheLEDintothesmallholeinthebackofthemotorontheterminal.Bendthewirebackup

andsecureittightlyarounditselfsoitwon’tcomeoff.4. Dothisfortheotherlegandsecondmotorterminal.5. Giveyourshaftaspin.Whathappened?Writeithere:

____________________________________________________________________________________________________

6. Canyouuseyouralligatorwiresandworkwithanotherlabgroup’smotortoseeifyoucangetyourLEDtolightupbrighterandlonger?Ifyoudon’thaveaDMM,completedatatable#1belowtofinishupthelab.IfyoudohaveaDMM,skipthisstepandmoveontothenextsteptocompletedatatables#2and3.

7. IfyouhaveaDMM,completedatatable#2.8. Forthenextpartofthelab,attachthepropellertothemotorshaftsecurely.9. Haveonestudentholdthemotor(ormountitontheedgeofastackofbooksandsecurewithtape).10. RemovetheDMMprobesandattachtheLEDtothebackofthemotor.11. Pluginyourhairdryer.12. Aimthehairdryeratthepropeller.WhathappenstotheLED?13. Playwiththedistanceandangleofthehairdryer.Whatisthebestplacetoblowairoverthepropellersso

theLEDlightsupthebrightest?Writeithere:_____________________________________________________________________________________________________________

14. RemovetheLEDandattachtheDMMprobestothemotorterminals.15. Completedatatable#3.

Exercises

1. HowandwhydoestheLEDchangecolors?(Spintheshaftinoppositedirectionstocauseelectricitytoflowinadifferentdirection.TheLEDisbi‐polar,whichmeansthereareactuallytwoLEDsinside,linedupoppositeeachother.Whenelectricityflowsoneway,theredLEDlightsupbutnotthegreen.Whenitflowstheotherway,thegreenLEDlightsupbutnotthered.)

2. Whydoesitmatterwhichwaytheairflowsoverthepropeller(atthefrontortheback)?3. Whichsetofconditionsgaveyouthemostenergyfromyourgenerator?(Refertoyourdatatable).



Lesson#16:MotorsandGeneratorsStudentWorksheet

Name______________________________________________________________________

OverviewInsideyourmotorarepermanentmagnetsandanelectromagnet(thecopperthingwrappedaroundthemiddle).Normally,you’dhookupabatterytothetwotabs(terminals)atthebackofthemotor,andyourshaftwouldspin.However,ifyouspinthemotorshaftwithyourfingers,you’llgenerateelectricityattheterminals.Buthowisthatpossible?That’swhatthislabexperimentisallabout.

WhattoLearnStudentswilllearntheroleofelectromagnetsintheconstructionofelectricmotorsandelectricgenerators.

Materials

9‐18VDChobbymotor Bi‐polarLED 2alligatorwires Propeller Hairdryer(Youbroughtonefromhome,right?) Optional:DigitalMultimeter(DMM)frompreviousElectricityunit

LabTime

1. Takeyourmotorandopenupthetabsontheend(iftheyaredown).2. InsertonelegoftheLEDintothesmallholeinthebackofthemotorontheterminal.Bendthewirebackup

andsecureittightlyarounditselfsoitwon’tcomeoff.3. Dothisfortheotherlegandsecondmotorterminal.4. Giveyourshaftaspin.Whathappened?Writeithere:

____________________________________________________________________________________________________

5. Canyouuseyouralligatorwiresandworkwithanotherlabgroup’smotortoseeifyoucangetyourLEDtolightupbrighterandlonger?Ifyoudon’thaveaDMM,completedatatable#1belowtofinishupthelab.IfyoudohaveaDMM,skipthisstepandmoveontothenextsteptocompletedatatables#2and3.


Motors&GeneratorsDataTable#1

Movearoundtheroomtofindadditionallabpartnerstoworkwith.

NumberofMotorsConnected(ex:“2motorsinseries”or“3motorsinparallel”)

Brightness(Useascaleof1‐10where

10=brightest)

ExercisesAnswerthequestionsbelow:1. HowandwhydoestheLEDchangecolors?

2. Whydoesitmatterwhichwaytheairflowsoverthepropeller(atthefrontortheback)?

3. Whichsetofconditionsgaveyouthemostenergyfromyourgenerator?


6. Completethetablebelow:


RemovetheLEDandcliponaDMMprobetoeachterminaltomeasurethepeakvoltage.Usethe20VDCsettingontheDMM.

LabPartnerName NumberofVoltsGeneratedWhentheySpin

7. Attachthepropellertothemotorshaftsecurely.8. Haveonestudentholdthemotor(ormountitontheedgeofastackofbooksandsecurewithtape).9. RemovetheDMMprobesandattachtheLEDtothebackofthemotor.10. Pluginyourhairdryer.11. Aimthehairdryeratthepropeller.WhathappenstotheLED?12. Playwiththedistanceandangleofthehairdryer.Whatisthebestplacetoblowairoverthepropellersso

theLEDlightsupthebrightest?Writeithere:_____________________________________________________________________________________________________________

13. RemovetheLEDandattachtheDMMprobestothemotorterminals.14. Completethetable:



HairDryerSetting(Low,Med,High…?)

LocationfromPropeller(Example:4”behind,6”infront…)

VoltageGenerated(Don’tforgetunits!)

Exercises


1. HowandwhydoestheLEDchangecolors?

2. Whydoesitmatterwhichwaytheairflowsoverthepropeller(atthefrontortheback)?

3. Whichsetofconditionsgaveyouthemostenergyfromyourgenerator?


Lesson#17:Quick‘n’EasyDCMotorTeacherSection

OverviewToday,yougettofindouthowmagneticfieldsinteractwitheachotherandcausethingstorotate.Inthiscase,we’reusinganelectromagnetandapermanentmagnetsowecanturnourmotoronandoff.


ObjectivesKidswillmakeauni‐polarmotorusingascrewandapermanentmagnetthatconductselectricity.


AAbattery 5differentsizesofmetalscrews 6”insulatedwire Verystrongmagnet(disc‐shaped)coatedinmetalsoitconductselectricity,likeametal

neodymiummagnetfromthehardwarestoreortrywww.KJmagnetics.com(Part#DC2)

LabPreparation

1. Printoutcopiesofthestudentworksheets.2. Watchthevideoforthisexperimenttoprepareforteachingthisclass.3. ReadovertheBackgroundLessonReadingbeforeteachingthisclass.4. Precutthewireforthisclassandstripbothends.You’llneedonepieceforeachlabgroup.Youcan

alternativelycutanalligatorwireintwopiecesandstriptheendsyoucutsotheinnerwiresareexposed.Youneedtheindividualwirestotouchthemetalforthisexperiment.(Ifyouleavetheheadonthealligatorcliplead,you’llroastyourbattery.)


IfyouCOULDseparatethenorthfromthesouthpole,youcouldpointamagnet’ssouthpoletowardyournow‐separatednorthpole,anditwouldalwaysberepelled,nomatterwhatorientationitrotatedto.Normally,assoonasthemagnetisrepelled,ittwistsaroundandlinesuptheoppositepoleandSNAP!(theregoyourfingers.)Butifitwerealwaysrepelled,youcouldchaseitaroundtheroomorstickapinthroughitsoitwouldconstantlymoveandrotate.

Well,whatifwesneakilyuseelectromagnetism?Notethatyoucanuseametalscrew,ballbearing,orothermetalobjectthateasilyrotates.Ifyourmetalballbearingisalsomagnetic,youcancombineboththescrewandthemagnettogether.

FamousscientistMichaelFaradaybuiltthefirstoneofthesewhilestudyingmagnetismandelectricity,andhowtheybothfittogether.Here’swhathefiguredout:

Thecurrentfromthebatteryisflowingthroughthewire,creatingamagneticfieldaroundthewire,whichinteractswiththemagneticfieldinthegolddiskmagnet.Sincethewirecreatesamagneticfieldthatisperpendiculartothefieldinthegoldmagnet,themagnetfeelsapush,whichcausesittorotate.


Lesson

1. Watchyourfingersonthisexperiment–ifyou’renotcarefulandleaveyourwirecontactingthemagnettoolong,you’llroastyourbattery(andthat’sreallybad).

2. Oneofthebigmysteriesoftheuniverseiswhywecan’tseparatethenorthfromthesouthendofamagnet.Nomatterhowsmallyoubreakthatmagnetdown,you’llstillgetonesidethat’sattractedtothenorthandtheotherthat’srepelled.There’sjustnowayaroundthis!Oristhere?Whatifwesneakilyuseelectromagnetism?Thislabwillshowyouhow.

LabTime


2. Placeyourmagnetontheheadofthescrew.3. Putthepointofthescrewontheplusendofthebattery.Everythingshouldholdtogetherifyou’vegota

nice,strongmagnet.4. Fantheendsofoneendofthewireouttomakeitlooklikealittlepaintbrush.5. Holdthebatteryinyourhandwiththenegativesideup.6. Taketheotherendofthewireandpressitonthenegativeendofthebatterywithyourfinger.Holdthe

batterywiththerestofyourfingerssothatthemagnetdanglesaninchortwoabovethetable.7. Takethelittlewirepaintbrushendandbarelytouchthetopofthemagnet.Themagnetandscrewshould

starttospin!8. Note:Donotleavethepaintbrushwireattachedtothemagnetoryouwillroastyourbattery(which

mayexplode).9. Youmayneedtore‐centeryourscrew,especiallyonceyoureallygetitgoing.

Exercises

1. Howdoesthiswork?(Whenyoutouchthepaintbrushwiretothemagnet,electricitystartstoflow,whichcreatesamagneticfield.Thatmagneticfieldinteractswiththemagneticfieldinthemetalmagnet,andtheresultisthatitstartstorotate.Twomagneticfieldsareinteractingandcausingstufftorotate.)

2. Whathappensifyoureversethepolarityandattachthescrewtothenegativesideofthebattery?(Themagnetspinsintheoppositedirection.)

3. Howdoyougetyourmotortospinthefastest?(Makesurethescrewiscenteredonboththebatteryandthemagnet,andthatthewirebarelytouchesthemagnet.)


Lesson#17:Quick‘n’EasyDCMotorStudentWorksheet

Name______________________________________________________________________


OverviewOneofthebigmysteriesoftheuniverseiswhywecan’tseparatethenorthfromthesouthendofamagnet.Nomatterhowsmallyoubreakthatmagnetdown,you’llstillgetonesidethat’sattractedtothenorthandtheotherthat’srepelled.There’sjustnowayaroundthis!Oristhere?Whatifwesneakilyuseelectromagnetism?

WhattoLearnToday,yougettofindouthowmagneticfieldsinteractwitheachotherandcausethingstorotate.Inthiscase,we’reusinganelectromagnetandapermanentmagnetsowecanturnourmotoronandoff.

Materials

AAbattery 5differentsizesofmetalscrews 6”insulatedwire Verystrongmetalmagnet

LabTime

1. Placeyourmagnetontheheadofthescrew.2. Putthepointofthescrewontheplusendofthebattery.Everythingshouldholdtogetherifyou’vegota

nice,strongmagnet.3. Fantheendsofoneendofthewireouttomakeitlooklikealittlepaintbrush.4. Holdthebatteryinyourhandwiththenegativesideup.5. Taketheotherendofthewireandpressitonthenegativeendofthebatterywithyourfinger.Holdthe

batterywiththerestofyourfingerssothatthemagnetdanglesaninchortwoabovethetable.6. Takethelittlewirepaintbrushendandbarelytouchthetopofthemagnet.Themagnetandscrewshould

starttospin!7. Note:Donotleavethepaintbrushwireattachedtothemagnetoryouwillroastyourbattery

(whichmayexplode).8. Youmayneedtore‐centeryourscrew,especiallyonceyoureallygetitgoing.9. Completethetableforallthescrews,tryingeachoneoneitherthepositiveornegativeterminal.


QuickDCMotorDataTable

ScrewSize/Description(Example:2”brassscrew)

WhichTerminalistheScrewAttachedto?(positiveornegative)

SpinRateRateonscale:

(veryslow/slow/medium/fast/veryfast)

Exercises


1. Howdoesthisexperimentwork?

2. Whathappensifyoureversethepolarityandattachthescrewtothenegativesideofthebattery?

3. Howdoyougetyourmotortospinthefastest?


Lesson#18:HomemadeRelayShockersTeacherSection

OverviewRelaysareswitchesthatturnonandoffwithelectricity.TheycanbeNO(normallyopen)orNC(normallyclosed),dependingonhowyouhookthemup.Thisrelayexperimentwillactuallygiveanicebluesparkwhenfiredup,alongwithanicezaptothehandthattouchesitinjusttherightspot.Youcanalsousethisrelayinyourelectricityexperimentsasaswitchyoucanusetoturnthingsonandoffusingelectricity(insteadofyourfingersmovingaswitch).


ObjectivesKidswilllearnhowtouseanelectricalswitchthatusesmagnetisminordertooperate.Andtheycanshockthemselvessillywiththisexperiment.


Relay AAbatterycase 2AAbatteries LED Motor 9Vbatterywithclip Alligatorwires

LabPreparation

1. Printoutcopiesofthestudentworksheets.2. Watchthevideoforthisexperimenttoprepareforteachingthisclass.Thereareacoupleofdifferent

experimentsinthisvideo.3. ReadovertheBackgroundLessonReadingbeforeteachingthisclass.


Arelayisswitchyoucanturnonandoffusingelectricity.Itusesanelectromagnettoactivetheswitchinsideit.Relaysareoperatedwithalower‐powersignal,butcanswitchacircuitofahigh‐powersignal.Theyareoftenusedwhenmultiplecircuitsneedtobecontrolledbyonesignal.Thefirstrelaysusedwereinlong‐distancetelegraphcircuitsasrepeaters.Theywouldrepeattheincomingsignalfromonecircuitandretransmitittoanothercircuit.Thenextlab,Experiment19:TelegraphsandRelays,showsthisveryexperiment.

Therearemanydifferenttypesofrelays:latchingrelays(showninthisvideoandalsointheElectricityunitExperiment18:LatchingCircuits),reedrelays(refertoExperiment7:MagneticSensors),mercuryswitches(wherethecontactsarewettedwithmercury,contactor(usedforheavy‐dutyelectricmotorcircuits),solid‐state(whichdoesn’thaveanymovingcomponents),andmore.Inaddition,somerelaysareSPST(single‐polesingle‐throw)whileothersareDPDT(double‐poledouble‐throw).


Lesson

1. Sincetherearemultipleexperimentsinthevideo,watchitfirstbeforeteachingtheclass.ThestepsbelowintheLabTimesectionareformakingthebuzzerandswitchingontheLED.Note:youcanusea9Vbatteryinplaceofthe3batterycasesand6batteriesasshowninthevide–itmakestheexperimentaloteasiertodo.

2. Ifyoulookatthebackoftherelay(whereallthelittlemetaltabsarestickingout),itcanlookabitintimidating.It’sreallytwodifferentparts:

a. Thefirstpartisthecoil,andtheseareusuallylabeledassuchorhavetwohairlinewiresrunningtothem,orareorientedinadifferentdirectionfromtherestofthetabs.Thesearefortheelectromagnetinside.Whenyouenergizethecoil(connectthesetwotabsuptoabattery),therelayclicksonandswitchesthesecondpartofitself.

b. Thesecondpartistheswitch.Therearethreecontactsallinarow:Themiddlecontactisconnectedtoapieceofmetal.Theendofthemiddlecontactrestsagainstthetopcontactwhenthecoilisn’tenergized.Whenthecoilisenergized,itattractsthemiddlecontactdowntowarditself,sothemiddlenowtouchesthelowercontact.

c. Whenthecoilisnolongerenergized,themiddlecontactbreaksawayfromthelowercontactandfloatsbackuptotouchthetopcontact.It’slikeaswitchthatfloatsbetweentwocontacts,dependingoniftheelectromagnetisactiveornot.

d. Sincetherearetwocontactsthatthemiddlecontactcantouch,youcanconnecttherelaytoswitchoffyourcircuitwhenyouenergizetheelectromagnet,orhaveitturnonyourcircuit,dependingonwhichtwocontactsyouchoosetoconnectto.Rememberthatyouneedtoincludethemiddlecontacteverytimeyouconnecttoitfortherelaytowork.

3. Walkthestudentsthrougheachpartoftherelaysotheyarecomfortablewhenwiringitup,whichmeansyouhavetobecomfortablewithallthosetabsonthebackoftherelay.Watchthevideo,asitexplainswhichonesareforthecoilandwhicharetheswitchtabs.

LabTime


Usingtherelayasaswitch:

2. Snaptheclipontothe9Vbattery.3. Connecttheredpositivewirefromthe9Vbatterytoanalligatorcliplead.Connecttheotherendofthe

alligatorclipleadtoonesideofthecoil(seevideotofindoutwhichtabonyourrelaythisis).4. Connecttheblacknegativewirefromthe9Vbatterytoanotheralligatorcliplead.5. Taptheotherendofthisalligatorclipleadontheothersideofthecoil(again,seevideotofindoutwhich

tabonyourrelaythisis).Yourrelayshould*click*.Don’tconnectthiswirepermanentlytotherelay.Justtapit.

6. Setthiscircuitaside.Leavethealligatorclipfromstep5nexttobutnottouchingtherelayterminal.7. InsertyourAAbatteriesintothecase.Flatside(minus)goestothespring.8. Attachonealligatorcliptoeachofthemetaltipsofthewiresfromthebatterycase.Makesureyou’vegota

goodmetal‐to‐metalconnection.Youshouldnowhavetwoalligatorclipsattachedtothebatterypack.9. Attachtheendofthealligatorclipthat’sconnectedtotheblackwire(negative)fromthebatterycasetothe

flatsideoftheLED.Itdoesn’tmatterwhatcolorthealligatorclipwireis.


10. Attachtheotheralligatorclipthat’sconnectedtotheredwire(positive)fromthebatterycasetothelongerLEDwire.Again,itdoesn’tmatterwhatcolorthealligatorclipwireis.

11. YourLEDshouldlightup!12. OnceyourLEDisilluminated,whathappensifyoutakeitoutandinsertitintheoppositewayintothe

circuit?(Reversethepolarity.)Doesitstillwork?13. Younowhavetwocircuits–onethatlightsuptheLEDandonethatmakestherelayclick.Let’scombine

themsothatwhentherelayclicks,itturnsontheLED.14. RemoveoneofthewiresfromtheLEDandreplaceitwithathirdwire.Spreadthisoutinabigcircleon

yourdesk.Whenyoutouchthetwofreealligatorclipsleadstogether,theLEDshouldstilllightup.15. Now,pulloveryourrelaycircuit.Cliponeofthefreealligatorclipleadstothesecondandthirdcontactof

therelayonthesamerowofcontactsofyourrelay.16. Energizeyourcoilbytapingthealligatorclipfromstep5totheterminalsoitclicks.Whathappens?Write

ithere:

_____________________________________________________________________________________________________

17. Movethealligatorclipfromterminal3toterminal1andthentapthecoiltoclicktherelay.Howdoesthischangeyourcircuit?Writeithere:______________________________________________________________________________________________________

18. CanyoureplacetheLEDwithamotor?Canyouswitchonthemotorusingtherelay?19. CanyoufigureoutacircuitthatwillmakebothmotorandLEDworkatthesametime?20. Drawoneoftherelaycircuitsthatworkedhere,labelingalltheparts:

Usingtherelayasabuzzer/shocker:

1. Removeallofthealligatorleadsfromtheprevioussteps.2. Wewanttowiretherelaysoitenergizesitself,becausewewantittodoitveryquickly.3. Cliponealligatorclipleadtothecoil,andtheotherendtothepositivewireofthe9Vbattery.4. Clipasecondalligatorcliptooneofthecontactsthattheinternalswitchisnormallytouchingwhenit’snot

energized.Theothersideofthealligatorclipwiregoestothenegativewireofthe9Vbattery.5. Connectathirdalligatorclipleadtothebottomcontactinthesamerowofcontactsastheleadfromstep3.

(findthecontactthatisnormallytouchingwhenthecoilisnotenergized),andtheotherendofthealligatorclipleadgoestotheothersideofthecoil.

6. Therelayshouldbebuzzing!Canyoufindthebluespark?Youcantouchit–theampsarelowsoit’sanice,safelittlezap.

7. Howdoesthiswork?Whydoestherelayengageitselfanddisengage?8. Drawthecircuitwiththethreewiresandbatteryandrelayhere(alsoindicatewheretotouchtoreceivea

zap):


Exercises

1. Isthereapermanentmagnetand/oranelectromagnetinsidearelay?(Electromagnet.)2. Whatmakestherelayaswitch?(Whentheelectromagnetinsideisenergized,therelayswitchesthingson

oroff,dependingonhowthecircuitisconnected.)3. Whatmakestherelayturnonandoff(*click*)?(Whenpowerisaddedtothetabsthatconnecttothe

electromagnet,theelectromagnetattractsthemetalcontact,whichmakestheclick.)4. Isthesamepowersourcethatactivatestherelayalsousedforthecircuitit’sswitching?(No,theyaretwo

differentcircuits,soyoucanusealow‐powersignaltoactivatetherelaybutrunhigh‐powerthroughtheswitchcontacts.)



Lesson#18:HomemadeRelayShockersStudentWorksheet

Name______________________________________________________________________

OverviewToday,yougettolearnhowtouseanelectricalswitchthatusesmagnetisminordertooperate.Andyoucanshockyourselfsillywiththisexperimentattheendwhenyouturnitintoabuzzer.

WhattoLearnRelaysareswitchesthatturnonandoffwithelectricity.TheycanbeNO(normallyopen)orNC(normallyclosed),dependingonhowyouhookthemup.Thisrelayexperimentwillactuallygiveanicebluesparkwhenfiredup,alongwithanicezaptothehandthattouchesitinjusttherightspot.Youcanalsousethisrelayinyourelectricityexperimentsasaswitchyoucanusetoturnthingsonandoffusingelectricity(insteadofyourfingersmovingaswitch).

Materials

Relay AAbatterycase 2AAbatteries LED Motor 9Vbatterywithclip Alligatorwires

LabTime

Thislabhastwoparts.Thefirstwalksyouthroughhowtousetherelayasaswitch,andthesecondshowshowtowireuptherelaysoit’sabuzzer/shocker.

Usingtherelayasaswitch:

1. Snaptheclipontothe9Vbattery.2. Connecttheredpositivewirefromthe9Vbatterytoanalligatorcliplead.Connecttheotherendofthe

alligatorclipleadtoonesideofthecoil(yourteacherwillshowyouhowtofindoutwhichtabonyourrelaythisis).

3. Connecttheblacknegativewirefromthe9Vbatterytoanotheralligatorcliplead.4. Taptheotherendofthisalligatorclipleadtotheothersideofthecoil(again,yourteacherwillshowyou

howtofindoutwhichtabonyourrelaythisis).Yourrelayshould*click*.Don’tconnectthiswirepermanentlytotherelay.Justtapit.

5. Setthiscircuitaside.Leavethealligatorclipfromstep5nexttobutnottouchingtherelayterminal.6. InsertyourAAbatteriesintothecase.Flatside(minus)goestothespring.7. Attachonealligatorcliptoeachofthemetaltipsofthewiresfromthebatterycase.Makesureyou’vegota

goodmetal‐to‐metalconnection.Youshouldnowhavetwoalligatorclipsattachedtothebatterypack.8. Attachtheendofthealligatorclipsthat’sconnectedtotheblackwire(negative)fromthebatterycaseto

theflatsideoftheLED.Itdoesn’tmatterwhatcolorthealligatorclipwireis.


9. Attachtheotheralligatorclipthat’sconnectedtotheredwire(positive)fromthebatterycasetothelongerLEDwire.Again,itdoesn’tmatterwhatcolorthealligatorclipwireis.

10. YourLEDshouldlightup!11. OnceyourLEDisilluminated,whathappensifyoutakeitoutandinsertitintheoppositewayintothe

circuit?(Reversethepolarity.)Doesitstillwork?12. Younowhavetwocircuits–onethatlightsuptheLEDandonethatmakestherelayclick.Let’scombine

themsothatwhentherelayclicks,itturnsontheLED.13. RemoveoneofthewiresfromtheLEDandreplaceitwithathirdwire.Spreadthisoutinabigcircleon

yourdesk.Whenyoutouchthetwofreealligatorclipleadstogether,theLEDshouldstilllightup.14. Nowpulloveryourrelaycircuit.Cliponeofthefreealligatorclipleadstothesecondandthirdcontactof

therelayonthesamerowofcontactsofyourrelay.15. Energizeyourcoilbytapingthealligatorclipfromstep5totheterminalsoitclicks.Whathappens?Write

ithere:

_____________________________________________________________________________________________________

16. Movethealligatorclipfromterminal3toterminal1andthentapthecoiltoclicktherelay.Howdoesthischangeyourcircuit?Writeithere:______________________________________________________________________________________________________

17. CanyoureplacetheLEDwithamotor?Canyouswitchonthemotorusingtherelay?18. CanyoufigureoutacircuitthatwillmakebothmotorandLEDworkatthesametime?19. Drawoneoftherelaycircuitsthatworkedhere,labelingalltheparts:


Usingtherelayasabuzzer/shocker:

1. Removeallofthealligatorleadsfromtheprevioussteps.2. Wewanttowiretherelaysoitenergizesitself,becausewewantittodoitveryquickly.3. Cliponealligatorclipleadtothecoil,andtheotherendgoestothepositivewireofthe9Vbattery.4. Clipasecondalligatorcliptooneofthecontactsthattheinternalswitchisnormallytouchingwhenit’snot

energized.Theothersideofthealligatorclipwiregoestothenegativewireofthe9Vbattery.5. Connectathirdalligatorclipleadtothebottomcontactinthesamerowofcontactsastheleadfromstep3.

(findthecontactthatisnormallytouchingwhenthecoilisnotenergized),andtheotherendofthealligatorclipleadgoestotheothersideofthecoil.

6. Therelayshouldbebuzzing!Canyoufindthebluespark?Youcantouchit–theampsarelowsoit’sanice,safelittlezap.

7. Howdoesthiswork?Whydoestherelayengageitselfanddisengage?8. Drawthecircuitwiththethreewiresandbatteryandrelayhere(alsoindicatewheretotouchtoreceivea

zap):

Exercises


1. Isthereapermanentmagnetand/oranelectromagnetinsidearelay?

2. Whatmakestherelayaswitch?

3. Whatmakestherelayturnonandoff(*click*)?

4. Isthesamepowersourcethatactivatestherelayalsousedforthecircuitit’sswitching?


Lesson#19:RelaysandTelegraphsTeacherSection

ThisisaBonusLab,meaningthatit’sinadditiontotheexperimentsthekidsgettodothroughoutthecourse.Feelfreetoskipthislabifthematerialsareoutofyourbudget,orsaveitasatreatfortheendoftheyear.Notethatthiscircuitisparticularlysensitiveandtrickytobuild,sohaveacoupleofextraadults(thehandy,DIYtype)tohelpyouwhenyoudothislab.

OverviewRelaysaretelegraphs,andtheybotharebasically“electricalswitches.”Thismeansyoucanturnsomethingonandoffwithouttouchingit–youcanuseelectricitytoswitchsomethingelseonoroff,aswedidinthelastexperiment.Inthislab,we’regoingtobuildourownrelaythatwillattractastripofmetaltomakeourtelegraph”click”eachtimeweenergizethecoil.


ObjectivesKidswilllearntheroleofelectromagnetsinelectricalcircuitsthatincludeelectricmotors,electricgenerators,andsimpledevicessuchasdoorbellsandearphones.


Blockoffoamabout6”square Sandpaper Alligatorwires Batterycase AAbatteries Filmcanisterorsimilar 2‐4”nail Magnetwire Brassfasteners 1/2″stripfromasteelsoupcanfortheclicker Paperclip Hotgluegun Scissors Tape

LabPreparation

1. Printoutcopiesofthestudentworksheets.2. Watchthevideoforthisexperimenttoprepareforteachingthisclass.3. ReadovertheBackgroundLessonReadingbeforeteachingthisclass.4. Precutthemagnetwireorpre‐wrapthenailsusingthetechniquefromExperiment15:Electromagnetsto

shortenupthetimeforthislab.5. Precutthefoamblocks


6. Precutthesandpaper(orre‐usethesamesandpaperyou’vebeenusingtostriptheenameloffthemagnetwire).

7. Precutthesoupcaninto½”wideby3”longstrips.Eachlabteamneedsone.


Whydoesthiswork?Anytimeyourunelectricitythroughawire,amagneticfieldshowsup.We’remultiplyingthiseffectwhenwecoilthewirearoundanail.Anailwithwirewrappedarounditiscalledanelectromagnet.Thinkofitlikeamagnetyoucanturnonandoff.

Usingapaper‐clipswitch,wecanturntheelectricityonandsenditthroughtheelectromagnet,turningtheordinarynailandwireintoamagnet.Whenwereleasethepaper‐clipswitch,thecurrent(electricity)stopsflowingandourelectromagnetturnsbackintoordinarynailandwire.

Whentheelectromagnetisenergized(magnetized),itattractsthemetalstrip,whichcausesittoclickdownwards.Releasethepaper‐clipswitch,andthestripisnolongerattractedtothenail(becauseit’snolongeramagnet).

Whentheswitchison,it’samagnet.Whenit’soff,it’snotamagnet.Magnetsattractsteel,andthat’swhythestripbendsandclicks.It’samazingwecouldcommunicateoverthousandsofmilesthisway,butwedid,usingtelegraphsandrepeaters!

Lesson

1. IMPORTANT!Thisexperimentisverytrickytogetworkingright.You’llwanttopairupwithsomeonewho’shandyintheworkshopandhasakeeneyeandafeathertouchforadjustingtheclickerinthefinalstep.Someonewhoisapatient,fix‐ittypeofpersonwillbeabletohelpyougetthisprojectworkingwell.

2. Youdon’thavetodothisasalab.Youcanmakeoneasademoforwhenyouareteachingrelays(previousexperiment)toshowthekidshowarelayreallyworks.Foramorepermanentproject,useasmallblockofwoodinsteadofthefoamandhammerinyournail.

LabTime


2. Watchthevideoasyouwalkthroughthesesteps:3. Maketheelectromagnetfirst.Wrapthemagnetwirearoundthenail.(Morewrapsmeanmorepowerfor

yourmagnet,sousealot!)Youcaninsertanailintoadrillandwinditonslowspeed.4. Sandtheinsulationofftheendleads.5. InserttheAAbatteriesintotheircase.6. Sticktheelectromagnet,pointy‐enddown,intothefoam.Ifitwigglesaround,youwillneedtohotglueit

intoplacelater(notnow).7. Hotglueoneendoftheclicker(thesteelsoupcanpiece)tothetopofafilmcanister.8. Attachthebottomofthefilmcanistertothefoamwithhotglue,makingsurethetipoftheclickerisover

thenailhead.Donotgluethelidtothecanister!It’sabigplustohaveitrotateandbeadjustable.9. Adjustandbendtheclickersothattheelectromagnetandnailhaveatinyclearancebetweenthenailhead

andthemetalstrip.You’llbeadjustingthisconstantlyasyouplaywithyourrelay.10. Hotgluethebatterycasetothefoamofftooneside.


11. Removesomeoftheinsulationfromthewiresfromthebatterycase.Youneedmorewireexposedtowrapitaroundabrassfastener.

12. Windthefreeendoftheexposedwirefromthenegativeblackwireofthebatterycasearoundabrassfastenerandinsertitintothefoam.Makesureyou’reonlywrappingthepartyou’vestrippedoritwon’tmakeagoodconnection.

13. Bendapaperclipintoa“V”shape.14. Insertthebrassfastenerthroughthetipofthe“V”shapeandthenintothefoam.Donotuseglue.15. Wraponeoftheelectromagnetwiresaroundasecondbrassfastener,makingsuretoonlywrapthepartof

thewirethatyousanded,andinsertthefastenerintothefoamwithinreachofthepaperclip.Besurethesmallersideofthe“V”restsonthefoamsuchthatitdoesnotreachthebrassfastener;butthelargersideofthe“V”,whenpresseddown,does.Thisisyourswitch.

16. Clipanalligatorclipwireontothepositivebatterywire,theotherendconnectedtothelastelectromagnetwire.Again,makesureyou’reconnectingtothepartoftheelectromagnetwirethatissandedoritwon’tmakeagoodconnection.

17. Pushyourswitchtothe“ON”position(makeittouchthesecondbrassfastener),andtheelectromagnetshould*click*.

18. Troubleshooting:Ifitdoesn’tclick,moveyourelectromagnetupordown,changingthenail‐head‐to‐clickerdistanceuntilitclicks.Ifitsticks,it’stooclose.Ifitdoesn’tmoveatall,it’stoofaraway.Hotgluenailintorightposition.Notethattheclickerisbendable.Takeyourtime–thisisaprojectthatrequirespatienceandobservationtofigureoutwhat’sgoingon.Ifyou’refrustrated,STOP,takeabreath,helpsomeoneelse,andreturnlater.

ForAdvancedStudentsOnly!

Ifyou’vegottherelayworkingandyouwantmore,youcanmakeadualrelay.Dualrelaysarecalled“repeaters.”Theytakeanincomingsignaland“repeat”thesignalandsenditout.You’llfindusesforthiswhenyouwanttoincreasethesignalstrength.Therelaydetectstheweaker,olderoneandrepeatsoutanewer,strongersignalidenticaltoit.Whentelegraphandradiosignalsneedtotraverselongdistances,thisisthebasicideaofhowtheydoitonhighmountaintops.

Here’showyoucanmakeyourown:

1. You’llneedyourtelegraphwithaswitchfromtheprevioussteps.2. Makeasecondtelegraphwithouttheswitchonanewfoamslab.Windyourwirearoundthenail,sandthe

ends,glueyourfilmcanistertothesoupcanstrip,andputthewholethingonanewpieceoffoam.3. Thesecondelectromagnetusesthefirstrelayasaswitch.4. Connectoneofthewiresfromyournewelectromagnettothenegativebatterywire(don’tforgettosand

themagnetwirefirst!).5. Connectanalligatorclipleadfromthepositivebatterywiretothefirsttelegraph’s“clicker”piece.Make

sureyou’retouchingtheclickerandnottheglue.6. Connectthesecondelectromagnetwiretothefirsttelegraph’smetalpartofthenail.Itmusttouchthenail

part,notthewirepart,inordertoworkcorrectly.7. Clicktheoriginalswitchfromthefirsttelegraph.TheswitchnowcontrolsBOTHrelays.8. Ifyoumakethewiresbetweenthetwofoamslabslonger(say,50feet),youcouldrelaymessagesbackand

forth!

TroubleshootingRelays:Ifaclickerdoesn’twork,checktheclearance.Movetheelectromagnetupanddown,untilyoufindtheperfectclickingspot.Itneedstobecloseenoughtoclick,butfarenoughsoitwon’tstick.


Canyoumakeseveral“‘repeaters?”Repeatersaretelegraphs(relays)thatgetswitchedonbyeachother(afteraninitialinputfromyou).Canyouconnectthreeorfourtelegraphstogethersothattheygetswitchedoninsequence?

Exercises

1. Whydoesthesoupcanclickermove?(Whentheswitchison,thenailbecomesamagnet.Whenit’soff,it’snotamagnet.Magnetsattractsteel,andthat’swhythestripbendsandclicks.)

2. Doesthiscircuituseapermanentorelectromagnet?(Electromagnet)3. Whydoweneedmultipleturnsaroundanail?Whynotjustacouplewraps?(Anytimeyourunelectricity

throughawire,amagneticfieldshowsup.We’remultiplyingthiseffectwhenwecoilthewirearoundanail.Anailwithwirewrappedarounditiscalledanelectromagnet.)

4. Whatisthepaper‐clipswitchusedfor?(Usingapaper‐clipswitch,wecanturntheelectricityonandsenditthroughtheelectromagnet,turningtheordinarynailandwireintoamagnet.Whenwereleasethepaper‐clipswitch,thecurrentstopsflowingandourelectromagnetturnsbackintoordinarynailandwire.)

5. Howcanarelaybeusedinreallife?Givethreeexamples.(Aspartofthecircuitrytokeepthefridgecold,torepeatsignalsoverlongdistances,andasapositionindicatorusingamercuryswitch.)



Lesson#19:RelaysandTelegraphsStudentWorksheet

Name______________________________________________________________________

OverviewInthislab,we’regoingtobuildourownrelaythatwillattractastripofmetaltomakeourtelegraph‘click’eachtimeweenergizethecoil.

WhattoLearnRelaysaretelegraphs,andtheybotharebasically“electricalswitches.”Thismeansyoucanturnsomethingonandoffwithouttouchingit–youcanuseelectricitytoswitchsomethingelseonoroff,aswedidinthelastexperiment.

Materials

Blockoffoamabout6”square Sandpaper Alligatorwires Batterycase AAbatteries Filmcanisterorsimilar 2‐4”nail Magnetwire Brassfasteners 1/2″stripfromasteelsoupcanfortheclicker Paperclip Hotgluegun Scissors Tape

LabTime


2. Watchthevideoasyouwalkthroughthesesteps:3. Maketheelectromagnetfirst.Wrapthemagnetwirearoundthenail.(Morewrapsmeanmorepowerfor

yourmagnet,sousealot!)Youcaninsertanailintoadrillandwinditonslowspeed.4. Sandtheinsulationofftheendleads.5. InserttheAAbatteriesintotheircase.6. Sticktheelectromagnet,pointy‐enddown,intothefoam.Ifitwigglesaround,youwillneedtohotglueit

intoplacelater(notnow).7. Hotglueoneendoftheclicker(thesteelsoupcanpiece)tothetopofafilmcanister.8. Attachthebottomofthefilmcanistertothefoamwithhotglue,makingsurethetipoftheclickerisover

thenailhead.Donotgluethelidtothecanister!It’sabigplustohaveitrotateandbeadjustable.


9. Adjustandbendtheclickersothattheelectromagnetandnailhaveatinyclearancebetweenthenailheadandthemetalstrip.You’llbeadjustingthisconstantlyasyouplaywithyourrelay.

10. Hotgluethebatterycasetothefoamofftooneside.11. Removesomeoftheinsulationfromthewiresfromthebatterycase.Youneedmorewireexposedtowrap

itaroundabrassfastener.12. Windthefreeendoftheexposedwirefromthenegativeblackwireofthebatterycasearoundabrass

fastenerandinsertitintothefoam.Makesureyou’reonlywrappingthepartyou’vestrippedoritwon’tmakeagoodconnection.

13. Bendapaperclipintoa“V”shape.14. Insertthebrassfastenerthroughthetipofthe“V”shapeandthenintothefoam.Donotuseglue.15. Wraponeoftheelectromagnetwiresaroundasecondbrassfastener,makingsuretoonlywrapthepartof

thewirethatyousanded,andinsertthefastenerintothefoamwithinreachofthepaperclip.Besurethesmallersideofthe“V”restsonthefoamsuchthatitdoesnotreachthebrassfastener;butthelargersideofthe“V”,whenpresseddown,does.Thisisyourswitch.

16. Clipanalligatorclipwireontothepositivebatterywire,theotherendconnectedtothelastelectromagnetwire.Again,makesureyou’reconnectingtothepartoftheelectromagnetwirethatissandedoritwon’tmakeagoodconnection.

17. Pushyourswitchtothe“ON”position(makeittouchthesecondbrassfastener),andtheelectromagnetshould*click*.

18. Troubleshooting:Ifitdoesn’tclick,moveyourelectromagnetupordown,changingthenail‐head‐to‐clickerdistanceuntilitclicks.Ifitsticks,it’stooclose.Ifitdoesn’tmoveatall,it’stoofaraway.Hotgluethenailintotherightposition.Notethattheclickerisbendable.Takeyourtime–thisisaprojectthatrequirespatienceandobservationtofigureoutwhat’sgoingon.Ifyou’refrustrated,STOP,takeabreath,helpsomeoneelse,andreturnlater.

ExercisesAnswerthequestionsbelow:1. Whydoesthesoupcanclickermove?

2. Doesthiscircuituseapermanentorelectromagnet?

3. Whydoweneedmultipleturnsaroundanail?Whynotjustacouplewraps?

4. Whatisthepaper‐clipswitchusedfor?

5. Howcanarelaybeusedinreallife?Givethreeexamples.


Lesson#20:DCMotorTeacherSection

OverviewWe’reabouttomakeasimpleelectricmotorthatusesthemagneticfieldinteractionbetweenapermanentandelectromagnettorotate.


ObjectivesKidswilllearntheroleofelectromagnetsintheconstructionofelectricmotors.


Magnet Magnetwire(26gworkswell) Dcellbattery Twopaperclips(trytofindtheonesshowninthevideo,orelsebendyourownwithpliers) Sandpaper Fatrubberband

LabPreparation

1. Printoutcopiesofthestudentworksheets.2. Watchthevideoforthisexperimenttoprepareforteachingthisclass.3. ReadovertheBackgroundLessonReadingbeforeteachingthisclass.4. Precutthewire.5. Bendthepaperclipsusingpliers.6. Precutthesandpaperifyou’renotreusingthepiecesfrompreviouslabs.

Lesson

1. Makeoneoftheseaheadoftimeandshowittotheclass.Askthem:HowdoesTHATwork?2. Whenyourunelectricitythroughanywire,itturnsslightlyintoamagnet.Whenyoustackwiresontopof

eachother(asyoudidwiththecoilofwire),youmultiplythiseffectandgetabiggermagnet.3. ThecoilofwireistheO‐shapedring.Whenthesandedpartsofthe“ears”areconnectedtothepaperclip,

currentflowsthroughthecircuit.Whenthishappens,everythingconnectstogetherandturnsthecoilwireintoanelectromagnet,whichisthenattractedtothemagnetonthebattery.

4. WhentheO‐ringrotates,itmovesarounduntiltheun‐sandedportionbreakstheconnectionandturnsitbackintojustacoilofwire.Thecoilcontinuestofloataroundinacircleuntilithitsthesandedpartsagain,whichre‐energizesthecoil,turningitbackintoanelectromagnet,whichisnowattractedtothemagnetonthebattery,whichpullsitaroundagain…and‘rounditgoes!

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9. Theloopontherightendiswheretherotorearwillslipthrough.Slidetherotorintotheloops.10. Spintherotorgently.Itshouldspinwithoutwobbling.Readjustandbalancetherotoruntilit’scentered

andspinningfreely.11. Placethemagnetonthebattery.Ifitdoesn’tsticktothebattery,slideitunderarubberband.12. Youwanttherotortobeasclosetothemagnetaspossiblewithouthittingit.13. Giveitaspin,andadjustthedistanceasneededtokeeptherotorspinning.14. Troubleshooting:Usuallyproblemsarisebetweentheconnectionofthebatteryterminalsandpaperclips.

Holdthebatterywiththefingertipsinthecenterofeachbatteryendandsqueezetomakeagoodconnection.Ifitstillfailstospin,checkyourrotor:oneearshouldbecompletelysandedandtheothershouldhaveastripofinsulationdownitslength.Ifyou’restillhavingtrouble,checktheearstobesuretheyarestraight.Therotorneedstobeabletospinnicely,soensureitiswell‐balanced.Egg‐shapedrotorsjustwon’tturn.

Exercises


1. WilltheDCmotorworkwithoutthemagnet?

2. Whereistheelectromagnet?

3. Whydoesthiswork?


Lesson#21:HearingMagnetismTeacherSection

ThisisaBonusLab,meaningthatit’sinadditiontotheexperimentsthekidsgettodothroughoutthecourse.Feelfreetoskipthislabifthematerialsareoutofyourbudget,orsaveitasatreatfortheendoftheyear.Thisisafantasticdemonstrationpiecetoaddtoyourteachingbox,soevenifyouonlymakeoneforyourself,youcanstillshowthekidsthebasicprinciples.

OverviewWanttohearyourmagnets?We’regoingtouseelectromagnetismtolearnhowyoucanlistentoyourphysicslesson,andyou’llbesurprisedathowcommonthisprincipleisinyoureverydaylife.


ObjectivesKidswilllearntheroleofelectromagnetsintheconstructionofsimpledevicessuchasmicrophones,speakers,doorbellsandearphones.


Magnetwire Sandpaper 3nails 4differentmagnets Audioamplifier(RS#277‐1008) Audioplug(RS#42‐2420)

LabPreparation

1. Printoutcopiesofthestudentworksheets.2. Watchthevideoforthisexperimenttoprepareforteachingthisclass.3. ReadovertheBackgroundLessonReadingbeforeteachingthisclass.4. Ifyoualreadyhaveelectromagnetsfromapreviousexperiment,usethoseforthislab.Otherwise,windthe

wirearoundthenailusingadrillonlowspeed.Leave4”endsoneachone.Wrapthembetween50‐100times,likea50,75,and100.Ifyouareusingadrill,timeyourselffor4seconds,8,and12secondsofthedrillrunning.Puttheminthreeseparatebagsandlabelthebags.You’llneedtohandeachlabgrouponefromeachbagwhenyoustart.Iusedifferent‐coloredelectromagnetwireorthreedifferentlengthsofnailswhenIdothisonesoIcanquicklyseewhichiswhich.

5. Cutthesandpaperinto1‐2”squares,orusethesandpaperfromapreviouslab.Oneperlabgroup.

Lesson

1. We’regoingtoinverttheideasusedinExperiment23:HomemadeSpeakersintoabasicmicrophone.Althoughyouwon’tbeabletorecordwiththismicrophone,itwillshowyouhowthebasicsofamicrophoneandamplifierwork,andhowtoturnsoundwavesbackintoelectricalsignals.

2. Anamplifier’sjobistotakesmallelectricalvoltages(AKAthe‘input’)andmakethembigger(amplifythem).Then,weusuallyplugaspeakerorheadphonesintotheamplifierandthoseturnthebigger


electricalsignal(AKAthe‘output’)intosound.Soanysmallvoltagethatweplugintotheamplifier’sinputwillgetlargerandthenturnintosoundthroughthebuilt‐inspeaker.

3. Onewaytoshowthisistouseacoilofwireandamagnet.Ifyoutakeacoilofwireandmoveamagnetpast,around,orthroughit,youwillcreateasmallelectricalvoltage(andcurrent)inthewire.Infact,ifyouhaveenoughwireandabigenoughmagnet,andmovethemagnetfastenough,theelectricitycomingoutofthecoilofwirecanlightupalightbulb(thisishowanelectricgeneratorworks).

4. Sobacktotheamplifier:Ifwetakethevoltagefromourlittlecoil/magnetgenerator,andweputitintotheamplifier,we’llhearthesoundfromthespeakereachtimeitmakesavoltage.Ifwemovethemagnetbackandforthreallyfast,we’llhearafastclickingsound.Andifweweretomoveitsuper‐incredibly‐fast(fasterthanyoucouldwithyourhands),thenthoseclickswouldblendtogetherintoatone.Toneslikethisarewhatallsoundsaremadeof.

5. Infact,thisisexactlywhatamicrophonedoes.Manymicrophoneshaveamagnetandacoilofwireattachedtoaverythinpieceofplasticormetalthatvibrateswhensoundwaveshitit.Theplastic(ormetal)inturnmovesthecoilofwirenexttothemagnetsuper‐fast.Thenthiscausestheelectricvoltagetocomeoutofthecoil,andifyouplugitintoanamplifieritwillmakethesamesoundthatthemicrophoneheard,onlylouder.

LabTime


2. Windthemagnetwirearoundthenailtomaketheelectromagnet.Useadrillifyouwanttospeedthisup.3. Usesandpapertostripofftheenamelcoatingofbothendsofthemagnetwire.4. Taketheaudioplugapartbyuntwistingthecasingfromthemetalpin.5. Threadthemetalwiresfromtheelectromagnetthroughthemetalcasing,narrowendfirst.6. Threadoneofthewiresthroughthebottomholeofthemetalplugandfolditbackoverintoitself,twisting

tosecureitintoplace.Makesureyou’vesandedwelltomakeagoodmetalconnection.7. Putthesecondelectromagnetwirethroughtwoofthesidetabholes,twisttosecure.8. Wrapeachconnectionwithapieceoftapetoinsulatethemfromeachother.Sincethesewiresareexposed

inatightspace,it’seasyforthemtotoucheachotherandshort‐circuit.9. Twistthecasingbackontothemetalplug.10. Plugthisintoyouraudioamplifier.Youshouldhaveanelectromagnetpluggedintotheamplifier.11. Makesureyouhavea9Vbatteryinyouramplifier!12. Turnontheamplifier.Turnthevolumeallthewayup!13. Bringamagnetclosetotheelectromagnet,rubbingitalongitslength.Whathappened?14. Covertheelectromagnetlooselywithasheetofaluminum.Nowwavethemagnetaround.Whathappened?15. Completethedatatable.

Exercises

1. Whydoestheelectromagnetmakesoundwhenyoubringthepermanentmagnetclosetoit?(Whenthemagnetcomesclosetotheelectromagnet,itgetsmagnetizedinincrements,whichiswhatthesoundsareintheampastheatomsareliningup.)

2. Howisthislikeamicrophone?(Themagnetmovesinandoutatthefrequencyofyourvoicenexttoacoil,whichtransmitsyoursoundvibrationstoanelectricalsignal.Inourexperiment,wearephysicallymovingthemagnetnexttoacoilofwire,whichistransformingthatsignaltoanelectricalsignal.)


3. Whatdidthealuminumdototheelectromagnet?(Thealuminumsheetworkedagainstthemovingmagnetbycreatingeddycurrentsthatcanceledoutthemagnet’seffectontheelectromagnet,soyoudon’thearverymuchatall.)



Lesson#21:HearingMagnetismStudentWorksheet

Name______________________________________________________________________

OverviewWanttohearyourmagnets?We’regoingtouseelectromagnetismtolearnhowyoucanlistentoyourphysicslesson,andyou’llbesurprisedathowcommonthisprincipleisinyoureverydaylife.

WhattoLearnWhenamagnetmovesnexttoacoil,itcreatesanelectricalcurrentinthecoil.Inamicrophone,amagnetmovesatthefrequencyofyourvoicenexttoacoil,whichtransmitsyoursoundvibrationstoanelectricalsignal.

Materials

Magnetwire Sandpaper 3nails 4differentmagnets Audioamplifier(RS#277‐1008) Audioplug(RS#42‐2420)

LabTime

1. Windthemagnetwirearoundthenailtomaketheelectromagnet.Useadrillifyouwanttospeedthisup.2. Usesandpapertostripofftheenamelcoatingofbothendsofthemagnetwire.3. Taketheaudioplugapartbyuntwistingthecasingfromthemetalpin.4. Threadthemetalwiresfromtheelectromagnetthroughthemetalcasing,narrowendfirst.5. Threadoneofthewiresthroughthebottomholeofthemetalplugandfolditbackoverintoitself,twisting

tosecureitintoplace.Makesureyou’vesandedwelltomakeagoodmetalconnection.6. Putthesecondelectromagnetwirethroughtwoofthesidetabholes,twisttosecure.7. Wrapeachconnectionwithapieceoftapetoinsulatethemfromeachother.Sincethesewiresareexposed

inatightspace,it’seasyforthemtotoucheachotherandshortcircuit.8. Twistthecasingbackontothemetalplug.9. Plugthisintoyouraudioamplifier.Youshouldhaveanelectromagnetpluggedintotheamplifier.10. Makesureyouhavea9Vbatteryinyouramplifier!11. Turnontheamplifier.Turnthevolumeallthewayup!12. Bringamagnetclosetotheelectromagnet,rubbingitalongitslength.Whathappened?Writeithere:

___________________________________________________________________________________________________________

___________________________________________________________________________________________________________


13. Covertheelectromagnetlooselywithasheetofaluminum.Nowwavethemagnetaround.Whathappened?

___________________________________________________________________________________________________________

14. Completethedatatable.

HearingMagnetismDataTable

Whichelectromagnet?

Whichmagnetdidyouuse?

Whatdidyoudo? Whatdiditsoundlike?Loud,soft,rough,scratchy,clicky,etc.

100turns 2”rectangleRubbedamagnetcloseto

electromagnetLoudandscratchy


Exercises


1. Whydoestheelectromagnetmakesoundwhenyoubringthepermanentmagnetclosetoit?

2. Howisthislikeamicrophone?

3. Whatdidthealuminumdototheelectromagnet?


Lesson#22:RailAcceleratorTeacherSection

ThisisaBonusLab,meaningthatit’sinadditiontotheexperimentsthekidsgettodothroughoutthecourse.Feelfreetoskipthislabifthematerialsareoutofyourbudget,orsaveitasatreatfortheendoftheyear.

OverviewWe’regoingtobuildontheExperiment17:Quick‘n’EasyDCMotortomakeatinyrailaccelerator.Ifyoumakeitanylargerthanthis,you’llneedapowerplantandafiringrangetooperateit.


ObjectivesWe’regoingtocreatetwomagneticfieldsatrightangles(perpendicular)toeachother.Whenthishappens,itcausesthingstomove,spin,rotate,androlloutoftheway.We’regoingtofocusthisdowntomakingatinysetofwheelszipdownatrackpoweredonlybymagnetism.


Cardboardorposterboard Aluminumfoil Hotglueordouble‐sidedstickytape Scissors Wirecoathanger Twoverytiny,neodymiummetal‐coateddiscmagnets(www.kjmagnetics.comPart#D21) 9Vbatterywithclip 2alligatorclipleads Pliersorvicegripstocutthecoathanger Stopwatch Rulerormeasuringtape

LabPreparation

1. Printoutcopiesofthestudentworksheets.2. Watchthevideoforthisexperimenttoprepareforteachingthisclass.3. ReadovertheBackgroundLessonReadingbeforeteachingthisclass.4. Cutthewirecoathangerinto2”stripsusingapairofvicegrips.Cuttheendsneatlysothemagnetssit

evenlyonthecutsurface.(Refertovideo.)

Lesson

1. ThisrailacceleratorisreallyjusttwoofthemotorsfromExperiment17:Quick‘n’EasyDCMotorconnectedtogether.Insteadofwire,weareusinganaluminumrail.Themagneticfieldintherailcreatesaforceperpendiculartothetinymagnet’smagneticfield.Thesetwomagneticfieldsinteract,causingthelittlewheelstoroll.

2. Ifyouhavethewheelson‘backwards’(oryourbatteryconnectedbackwards),yourwheelswillrolltoward(insteadofaway)fromyou.


3. Troubleshooting:Ifyoudropyourwheelsfromtoohighup,you’llknocktheaxleoff‐centerandthewheelswon’troll.Ifyourwheelsstilldon’troll,fliponeofthemagnetsaround(theymustbeinoppositedirectionsforthistowork!).Also,makesureyou’vegotafresh9Vbatteryandgoodelectricalconnectionbetweenyourclipsandthetrack.

LabTime


2. Havethestudentsmakedifferentlengthsoftrackasshowninthedatatable.Theywillrotatearoundtheroom,tryingouttheirlittlewheelsondifferenttracksandtakingdatameasurements.

3. Assigneachteamadifferenttracklength.Makesureeveryoneknowswhichtrackthattheyarecreating.4. Cutouttwostripsofaluminumfoil(refertodatatableforlength).Thewidthisapprox2‐3”wide.5. Usingglueortape,stickthealuminumstripsdownonyourposterboardafinger’s‐widthapart(abouta

halfinch).Ifyou’reusingtape,tapeonlytotheundersideofthefoil,notthetopside.6. Cuta2”longstraightpiecefromyourwirecoathangerusingvisegrips.7. Placethewheelateachend,placingthewireinthecenter.Theyshouldstickbythemselves.Makethemas

centeredaspossible.8. Attachthecliptoyourbattery.9. Attachonealligatorwiretothewirefromyour9Vbattery.Theotherendofthiswireclipsontoonesideof

thealuminumtrack.10. Attachasecondalligatorwiretotheotherwirefromyour9Vbattery.Theendofthiswireclipsontothe

othersideofthealuminumtrack.11. Setyourwheelsgentlyonthetrackandseeiftheytakeoff.Iftheydon’t,trythesethings:

a. Ifyoudropyourwheelsfromtoohighup,you’llknocktheaxleoff‐centerandthewheelswon’troll.b. Ifyourwheelsstilldon’troll,fliponeofthemagnetsaround.Themagnetsmustbeinopposite

directionsforthistowork.c. Makesureyou’vegotafresh9Vbattery.d. Doyouhaveagoodelectricalconnectionbetweenyourclipsandthetrack?Notapeintheway?

12. DoNOTleavethewheelsonthetrackiftheyarenotmoving.Thiswillshortcircuityourbatteryandtoastit(notagoodthing).


Exercises

1. Dothemagnetsneedtobeoppositeinorderforthistowork?(Yes,theymustbeperpendiculartothetrackandtothedirectionofthecurrentflow.)

2. Whydothewheelsmove?(Whenelectricityflowsthroughthealuminumrail,themagneticfieldintherailcreatesaforceperpendiculartothetinymagnet’smagneticfield.Thesetwomagneticfieldsinteract,causingthelittlewheelstoroll.)

3. Whichtrackworksthebest?(Refertoyourdatatable.)



Lesson#22:RailAcceleratorStudentWorksheet

Name______________________________________________________________________

OverviewWe’regoingtobemakingatinysetofwheelzipdownatrack.Thisishowrollercoastersandfasttrainsmovedowntherail,poweredonlybymagnetism.

WhattoLearnTwomagneticfieldsatrightangles(perpendicular)interacttoeachothertocausesthingstomove,spin,rotate,androlloutoftheway.

Materials

Cardboardorposterboard Aluminumfoil Hotglueordouble‐sidedstickytape Scissors Wirecoathanger

Twoverytiny,neodymiummetal‐coateddiscmagnets

9Vbatterywithclip 2alligatorclipleads Stopwatch Rulerormeasuringtape

LabTime

1. Eachlabgroupwillbeassignedtomakeadifferentlengthoftrackasshowninthedatatable.2. Yourgroupwillrotatearoundtheroom,tryingoutyourwheelsondifferenttracksandtakingdata

measurements.3. Yourteacherwillassignyourtracklengthtoyounowsoyoucanbuildit.Assoonasyouknowwhichone

youarebuilding,gotothenextstep.4. Cutouttwostripsofaluminumfoil(refertodatatableforlength).Thewidthisapprox2‐3”wide.5. Usingglueortape,stickthealuminumstripsdownonyourposterboardafinger’s‐widthapart(abouta

halfinch).Ifyou’reusingtape,tapeonlytotheundersideofthefoil,notthetopside.6. Cuta2”longstraightpiecefromyourwirecoathangerusingvisegrips.7. Placethewheelateachend,placingthewireinthecenter.Theyshouldstickbythemselves.Makethemas

centeredaspossible.8. Attachthecliptoyourbattery.9. Attachonealligatorwiretothewirefromyour9Vbattery.Theotherendofthiswireclipsontoonesideof

thealuminumtrack.10. Attachasecondalligatorwiretotheotherwirefromyour9Vbattery.Theendofthiswireclipsontothe

othersideofthealuminumtrack.11. Setyourwheelsgentlyonthetrackandseeiftheytakeoff.Iftheydon’t,trythesethings:

a. Ifyoudropyourwheelsfromtoohighup,you’llknocktheaxleoff‐centerandthewheelswon’troll.b. Ifyourwheelsstilldon’troll,fliponeofthemagnetsaround.Themagnetsmustbeinopposite

directionsforthistowork.c. Makesureyou’vegotafresh9Vbattery.d. Doyouhaveagoodelectricalconnectionbetweenyourclipsandthetrack?Notapeintheway?

12. DoNOTleavethewheelsonthetrackiftheyarenotmoving.Thiswillshortcircuityourbatteryandtoastit(notagoodthing).



RailAcceleratorDataTable

LabGroupNameLengthofTrack(feet,cm,inches…?)

TimetoTravelLength(seconds)

AverageSpeed(Speed=Length÷Time)


Exercises


1. Dothemagnetsneedtobeoppositeinorderforthistowork?

2. Whydothewheelsmove?

3. Whichtrackworksthebest?


Lesson#23:HomemadeSpeakersTeacherSection

ThisisaBonusLab,meaningthatit’sinadditiontotheexperimentsthekidsgettodothroughoutthecourse.Feelfreetoskipthislabifthematerialsareoutofyourbudget,orsaveitasatreatfortheendoftheyear.

OverviewAlexanderGrahamBelldevelopedthetelegraph,microphone,andtelephonebackinthelate1800s.We’llbetalkingaboutelectromagnetisminalaterunit,butwe’regoingtocoverafewbasicsheresoyoucanunderstandhowloudspeakerstransformanelectricalsignalintosound.


ObjectivesKidswilllearntheroleofelectromagnetsintheconstructionofsimpledevicessuchasmicrophones,speakers,doorbellsandearphones.


Foamplate Plasticcup Sheetofcopypaper 3businesscards MagnetwireAWG30or32(RS#278‐1345) 2‐4neodymiummagnets(usethesefrompreviousexperiments) Discmagnet(1”donut‐shapedmagnet)(RS#64‐1888) Indexcardsorstiffpaper Plasticdisposablecup Tape Hotgluegun Scissors 1audioplug(RS#42‐2420)orothercablethatfitsintoyourstereo(iPODsandothersmall

devicesarenotrecommendedforthisproject–youneedsomethingwithbuilt‐inamplifierlikeanoldboombox)

LabPreparation

1. Printoutcopiesofthestudentworksheets.2. Watchthetwovideosforthisexperimenttoprepareforteachingthisclass.Youcanshowthefirstvideoto

yourstudentssoyoudon’thavetosearchforanyfancyequipment.3. Haveoneboomboxatthefrontoftheroomforstudentstotesttheirspeakerswith.4. ReadovertheBackgroundLessonReadingbeforeteachingthisclass.5. Youcanhavesomestudentsmaketheirspeakersfromthefoamplate,othersusingtheplasticcupsoyou

cancompare.Trydifferentsizesofplatesandcupsaswell.Attheendofthelab,havethestudentscharttheirresultstogethertofindthebestcombinationformakingaspeaker.



Let’stalkaboutthetelegraph.Atelegraphisasmallelectromagnetthatyoucanswitchonandoff.Theelectromagnetisasimplelittlethingmadebywrappinginsulatedwirearoundanail.Anelectromagnetisamagnetyoucanturnonandoffwithelectricity,anditonlyworkswhenyouplugitintoabattery.

Anytimeyourunelectricitythroughawire,youalsogetamagneticfield.Youcanamplifythiseffectbyhavinglotsofwireinasmallspace(hencewrappingthewirearoundanail)toconcentratethemagneticeffect.Theoppositeistruealso–ifyourubapermanentmagnetalongthelengthoftheelectromagnet,you’llgetanelectriccurrentflowingthroughthewire.Magneticfieldscauseelectricfields,andelectricfieldscausemagneticfields.Gotit?

Amicrophonehasasmallelectromagnetnexttoapermanentmagnet,separatedbyathinspace.Thecoilisallowedtomoveabit(becauseit’slighterthanthepermanentmagnet).Whenyouspeakintoamicrophone,yourvoicesendssoundwavesthatvibratethecoil,andeachtimethecoilmoves,itcausesanelectricalsignaltoflowthroughthewires,whichgetspickedupbyyourrecordingsystem.

Aloudspeakerworkstheoppositeway.Anelectricalsignal(likemusic)zingsthroughthecoil(whichisalsoallowedtomoveandattachedtoyourspeakercone),whichisattractedorrepulsedbythepermanentmagnet.Thecoilvibrates,takingtheconewithit.Theconevibratestheairarounditandsendssoundwavestoreachyourear.

Ifyouplacedyourhandoverthespeakerasitwasboomingoutsound,youfeltsomethingagainstyourhand,right?That’sthesoundwavesbeinggeneratedbythespeakercone.Eachtimethespeakerconemovesaround,itcreateavibrationintheairthatyoucandetectwithyourears.Fordeepnotes,theconemovesthemost,andalotofairgetsshovedatonce,soyouhearalownote.Whichiswhyyoucanblowoutyourspeakersifyourbassiscrankeduptoomuch.Doesthatmakesense?

Lesson

1. We’regoingtodemonstratehowtouseasignalgeneratortodriveaspeakeratdifferentfrequenciesinthevideo(right).Weevenbroughtinspecialist(withverygoodhearing!)todetectthefullrangeofsoundandusedaspecialmicrophoneduringrecording,soyoushouldhearthesamethingwedidduringthetesting.Youcanshowthisvideotoyourstudents.

2. We’vecomealongwaywiththismagnetismthingandhopefullyyou’refeelingprettygoodabouthowmagnetismworksandwhatitdoes.Nowwe’regoingtousewhatwe’velearnedtomakesimpleversionsoftwogadgetsthatyouuseeveryday.

3. Let’sstartwiththeslightlysimplergadget.Now,tounderstandwhat’shappeninghere,weneedtorecap:Remember,thatelectricityismovingelectrons,andwhatdomovingelectronscreate?Amagneticfield.

4. Also,rememberthatamagneticfield,whenmovednearametalthatcanconductelectricity,willcreateanelectriccurrentinthatmetal.

5. Magnetismcancreateelectricityandelectricitycancreatemagnetism.Now,let’sgowaybackintimeandtrytoremembertheworkwedidwithsoundinUnit6.Soundisvibrations.Ifsomethingvibratesbetweenafrequencyof20‐20,000Hzourearscandetectitassound.

6. Tomakeaspeaker,weneedtosomehowmakesomethingvibrate.“Hmmm,Iwonderifthismagnetism/electricitycouldsomehowbeusefulhere.”

7. Sowhat’sgoingonwithaspeaker?Whatmakesitwork?Okay,here’sthedeal.Theradioprovidestheelectricitythatgetspumpedthroughthewires.Theradioveryquicklypumpselectricityinonedirectionandthenswitchestopumpitintheotherdirection.Thismovementofelectronsbackandforthcreatesamagneticfieldinthecoilofwire.


8. Sincetheelectricitykeepsreversing,themagneticfieldkeepsreversing.Basically,thepolesontheelectromagnetformedbythecoilgofromnorthtosouthandbackagain.Sincethepoleskeepreversing,thepermanentmagnetyouhavetapedtothecupkeepsgettingattracted,thenrepelled,attracted,thenrepelled.Thiscausesvibrations.

9. Thespeakercone(orcup,asinthespeakerwe’regoingtomake)that’sstrappedtothecoilandmagnetactsasasoundcone.Themagnetcausesthesoundconetovibrateandsinceit’srelativelylarge,itcausesairtovibrate.Thisisthesoundthatyouhear.

10. Almostallspeakersworkjustliketheoneyouaregoingtocreatenow.Theyjustusefanciermaterialssothatthesoundislouderandclearer.

11. Thesespeakersaremadefromcheapmaterialsandarefordemonstrationpurposesonly…theydonothaveanamplifier,soyou’llneedtoplaceyourearclosetothespeakertodetectthesound.DONOTconnectthesespeakersuptoyouriPODorotherexpensivestereoequipment,asthesespeakersareverylowresistance(lessthan2ohms)andcandamageyoursoundequipmentifyou’renotcareful.Thebestsourceofmusicforthesespeakersisanoldboomboxwithaplacetopluginyourheadphones.

LabTime


2. Watchthevideofirstsoyoucanshowthekidshowtobuildtheirspeakers!Herearethebasicstepsfromthevideo.

3. Cutabusinesscardinhalflengthwise.Foldeachstripinhalf,andthenfoldthelengthsinhalfagainsoyouhaveaW‐shape.

4. Stackyourmagnetstogetherandrollasmallstripofcopypaperaroundthemagnets.Tapethepaperintoplace.Dothisonemoretime,soyounowhavetwopapercylindersleevesaroundyourmagnets.

5. Wrapthemagnetwire20‐50timesaroundthepapertube(keepthemagnetsinsidesothisstepiseasier).Securewithtape.

6. Carefullyremoveonlytheinsidepapersleeveanddiscard(youcantakethemagnetsoutwhenyoudothis).7. Trimonesideofthepapersoonesideofthecoilisnearthepaperedge.8. Hotgluetheuncutsideofthepapertubetothebottomofafoamplate.9. HotglueonesideoftheW‐shapeofthebusinesscardtothebottomofthefoamplate.YouwantaW‐shape

oneithersideofthepapertube,aninchortwoaway.10. Hotglueyourmagnetstothecenterofastiffpieceofcardboard.11. PlaceyourpapertubeoverthemagnetsandgluetheW‐shapestothecardboard.Theseareyour‘springs’.12. Taptheplatelightlywithyourfinger.Makesurethefoamplateisfreetobounceupanddown.13. Sandtheendsofeachmagnetwiretostripawaytheinsulation.14. Unscrewtheplasticinsulationfromtheaudioplugandwraponewirearoundeachterminal.Makesurethe

twocontactsandwiresdon’ttoucheachother,oryourspeakerwon’twork.Youcansecureeachconnectionwithtape.

15. Plugitintoyourboomboxandplayyourmusiconthehighestvolume.Youshouldhearthemusiccomingfromyourspeaker!

Exercises

1. Doesitmatterhowstrongthemagnetsare?(Yes,thestrongertheyare,thebetterthesignalyouhearfromthespeaker.)

2. Whatelsecanyouusebesidesafoamplate?(Plasticcups,paperplates…)


3. Whichworksbetter:alargerorsmallermagnetwirecoil?(Larger)4. Howcanyoudetectmagneticfields?(Withacompass)5. Howdoesanelectromagnetwork?(Whenyouputelectricitythroughthewire,itturnsitintoamagnet.)6. Howdoesyourspeakerwork?(RefertotheBackgroundReadingSection.)7. Isaspeakerthesameasamicrophone?(No–theyareopposite.RefertotheBackgroundReadingSection.)8. Doestheshapeandsizeoftheplatematter?Whatifyouuseaplasticcup?(Yes–shapeandsizedomatter!)



Lesson#23:HomemadeSpeakersStudentWorksheet

Name______________________________________________________________________

OverviewWe’llbemakingdifferentkindsofspeakersusinghouseholdmaterials(likeplasticcups,foamplates,andbusinesscards!),butbeforewebegin,weneedtomakesureyoureallyunderstandafewbasicprinciples.

WhattoLearnAnelectricalsignal(likemusic)zingsthroughthecoil(whichisalsoallowedtomoveandattachedtoyourspeakercone),whichisattractedorrepulsedbythepermanentmagnet.Thecoilvibrates,takingtheconewithit.Theconevibratestheairarounditandsendssoundswavestoreachyourear.

Materials

Foamplate(paperandplasticdon’tworkaswell) Sheetofcopypaper 3businesscards MagnetwireAWG30or32(RS#278‐1345) 2‐4neodymiumorsimilar(rareearth)magnets Discmagnet(1”donut‐shapedmagnet)(RS#64‐1888) Indexcardsorstiffpaper Plasticdisposablecup Tape Hotgluegun Scissors 1audioplug(RS#42‐2420)orothercablethatfitsintoyourstereo(iPODsandothersmall

devicesarenotrecommendedforthisproject–youneedsomethingwithbuilt‐inamplifier)

LabTime

1. Cutabusinesscardinhalflengthwise.Foldeachstripinhalf,andthenfoldthelengthsinhalfagainsoyouhaveaW‐shape.

2. Stackyourmagnetstogetherandrollasmallstripofcopypaperaroundthemagnets.Tapethepaperintoplace.Dothisonemoretime,soyounowhavetwopapercylindersleevesaroundyourmagnets.

3. Wrapthemagnetwire20‐50timesaroundthepapertube(keepthemagnetsinsidesothisstepiseasier).Securewithtape.

4. Carefullyremoveonlytheinsidepapersleeveanddiscard(youcantakethemagnetsoutwhenyoudothis).

5. Trimonesideofthepapersoonesideofthecoilisnearthepaperedge.6. Hotgluetheuncutsideofthepapertubetothebottomofafoamplate.7. HotglueonesideoftheW‐shapeofthebusinesscardtothebottomofthefoamplate.YouwantaW‐shape

oneithersideofthepapertube,aninchortwoaway.8. Hotglueyourmagnetstothecenterofastiffpieceofcardboard.9. PlaceyourpapertubeoverthemagnetsandgluetheW‐shapestothecardboard.Theseareyour‘springs’.


10. Taptheplatelightlywithyourfinger.Makesurethefoamplateisfreetobounceupanddown.11. Sandtheendsofeachmagnetwiretostripawaytheinsulation.12. Unscrewtheplasticinsulationfromtheaudioplugandwraponewirearoundeachterminal.Makesure

thetwocontactsandwiresdon’ttoucheachother,oryourspeakerwon’twork.Youcansecureeachconnectionwithtape.

13. Plugitintoyourboomboxandplayyourmusiconthehighestvolume.Youshouldhearthemusiccomingfromyourspeaker!

Exercises


1. Doesitmatterhowstrongthemagnetsare?

2. Whatelsecanyouusebesidesafoamplate?

3. Whichworksbetter:alargerorsmallermagnetwirecoil?

4. Howcanyoudetectmagneticfields?

5. Howdoesanelectromagnetwork?

6. Howdoesyourspeakerwork?

7. Isaspeakerthesameasamicrophone?

8. Doestheshapeandsizeoftheplatematter?Whatifyouuseaplasticcup?


ElectromagnetismEvaluationTeacherSection

OverviewKidswilldemonstratehowwelltheyunderstandimportantkeyconceptsfromthissection.


ObjectivesStudentswillbetestedonthekeyconceptsofelectromagnetism:

1. Electriccurrentsproducemagneticfields.2. Magneticfieldscreateelectricalcurrents.3. Theroleofelectromagnetsintheconstructionofelectricmotors,electricgenerators,andsimpledevices

suchasdoorbellsandearphones.

Studentswillalsodemonstratetheseprinciples:

4. Howtobuildasimpleelectromagnet.5. Howtwomagneticfieldsinteracttocausemotion.

Materials(onesetforentireclass)

AAbatterycase 2AAbatteries Alligatorclipleads Plainnail(notwrappedinwire) Electromagnet(nailalreadywrappedinwire),endsnotsanded Electromagnet(nailalreadywrappedinwire),endssandeddown Paperclips 9‐18VDCmotor LED

LabPreparation

1. Printoutcopiesofthestudentworksheets,labpractical,andquiz.2. Haveatubofthematerialsinfrontofyouatyourdesk.Kidswillcomeupwhencalledanddemonstrate

theirknowledgeusingthesematerials.

LessonThestudentsaretakingtwoteststoday:thequizandthelabpractical.Thequiztakesabout20minutes,andyou’llfindtheanswerkeytomakeiteasytograde.

LabPracticalStudentswilldemonstrateindividuallythattheyknowhowtowireupacircuitandexplainhowelectricalenergycanbeconvertedtoheat,light,and/ormotion.Whileotherkidsarewaitingfortheirturn,theyhaveachoiceofthreedifferenthomeworkassignmentstogetstartedon.


ElectromagnetismEvaluation

StudentWorksheet

Overview:Today,you’regoingtotaketwodifferenttests:thequizandthelabpractical.You’regoingtotakethewrittenquizfirst,andthelabpracticalattheendofthislab.Thelabpracticalisn’tapapertest–it’swhereyougettoshowyourteacherthatyouknowhowtodosomething.

LabTest&Homework

1. Yourteacherwillcallyouupsoyoucansharehowmuchyouunderstandaboutelectromagnetismandhowitworks.Sincescienceissomuchmorethanjustreadingabookorcirclingtherightanswer,thisisanimportantpartofthetesttofindoutwhatyoureallyunderstand.

2. Whileyouarewaitingforyourturntoshowyourteacherhowmuchofthisstuffyoualreadyknow,yougettogetstartedonyourhomeworkassignment.Theassignmentisduenextweek,andhalfthecreditisforcreativityandtheotherhalfisforcontent,soreallyletyourimaginationflyasyouworkthroughit.Hereitis:Yourclassroomisgoingtobeconvertedintoaninteractivesciencemuseumnextweek.Youwillbeinchargeofoneofthestations.Youraudienceknowsnothingaboutmagnetism.Yourjobistodesignandbuildanexperimentthatteachesthestudentsinlowerlevelsanimportantconceptinoneofthefollowingareas:magnetismorelectromagnetism.Youwillgettoexplaintoyourstudentswhat’sgoingonasyoudemonstrateyourexperiment.Youcanhavethemwatchoractivelydosomethingatyourstation.Youwillbegradedbasedoncontentandcreativity,soreallyletyourmindgowild.(Hint:Ifyouweretheaudience,whatwouldyouwanttolearnaboutmost?)


ElectromagnetismQuizTeacher’sAnswerKey

1. Whydidn’tthecoilofwireonanelectromagnetworkwhenitwasn’thookeduptoabattery?Whatdoesthebatterydotothecoilofwire?(Thewireisjustwireuntilyouhaveelectricitypassingthroughit.Theelectricitycausesasmallmagneticfieldaroundthewire.Whenyoubundleandcoilthewireup,youmultiplythiseffecttocreateanelectromagnet.)

2. Whyisitcalledan‘electromagnet’andnotjusta‘magnet’?(Anelectromagnetisamagnetthatcanbeturnedoffandoffusingelectricity.)

3. What’sinsideaDCmotor?(Anelectromagnetandamagnet.)4. Howcanweuseelectromagnetstomakethingsmove?Giveanexample.(Whenyouenergizeacoilofwire,

youturnitintoanelectromagnet.Ifyoubringtwomagnetstogether,theirmagneticfieldsinteractandtheyrepeleachother,causingmotion.TheDCMotorisoneexample.Whentherotorisenergized,italignsitselfwiththemagnet.Asittriestoalignitself,itovershootsandsothattheun‐sandedportionbreakstheconnectionandtheelectromagnetturnsbackintojustacoilofwire.Thecoilcontinuestofloataroundinacircleuntilithitsthesandedpartsagain,whichre‐energizesthecoil,turningitbackintoanelectromagnet,whichisnowattractedtothemagnetonthebattery,whichpullsitaroundagain…androunditgoes!)

5. Giveanexampleofhowelectricitycausesmagnetism.(Whenyourunanelectricalcurrentthroughacoilofwire,youcandetectthemagneticfieldusingacompass.)

6. Giveanexampleofhowmagnetismcauseselectricity.(TheMotorsandGeneratorsexperimentisagreatexampleofthis.Whenyouspinthemotorshaft,youmoveanelectromagnetquicklypastapermanentmagnet,whichproducesajoltofelectricityatthemotor’stabs.YoucandetectthiscurrentwhentheLEDlightsuporbyadigitalmultimeter.)


ElectromagnetismQuiz

Name______________________________________________________

1. Whydidn’tthecoilofwireonanelectromagnetworkwhenitwasn’thookeduptoabattery?Whatdoesthebatterydotothecoilofwire?

2. Whyisitcalledan‘electromagnet’andnotjusta‘magnet’?

3. What’sinsideaDCmotor?

4. Howcanweuseelectromagnetstomakethingsmove?Giveanexample.

5. Giveanexampleofhowelectricitycausesmagnetism.

6. Giveanexampleofhowmagnetismcauseselectricity.


ElectromagnetismLabPracticalTeacher’sAnswerKey

Thisisyourchancetoseehowwellyourstudentshavepickeduponimportantkeyconcepts,andifthereareanyholes.Yourstudentsalsowillbeworkingontheirhomeworkassignmentasyoudothistestindividuallywiththestudents.

Materials:

AAbatterycase 2AAbatteries Alligatorclipleads Plainnail(notwrappedinwire) Electromagnet(nailalreadywrappedinwire),endsnotsanded Electromagnet(nailalreadywrappedinwire),endssandeddown Paperclips 9‐18VDCmotor LED

LabPractical:AskthestudentNote:Answersgiveninitalics!

Designandbuildanelectromagnetthatpicksuppaperclips.Batteryconnectstotheelectromagnetthathasbothendssandeddown.Whenthecoilisbroughtnexttothepaperclips,theyjumpupontotheelectromagnet.

Designandbuildanexperimentthatshowshowmagnetismcreateselectricity.ConnecttheLEDtothebackofthemotorattheterminals,andwhenyouspinthemotor,theLEDlightsup.Explaintotheteacherthatthere’sanelectromagnetinsidemovespastapermanentmagnet.


SampleProject:LinearAcceleratorHowtoUsetheScientificMethod

foraScienceFairProjectBeforewestartdivingintoexperimenting,researching,orevenwritingabouttheproject,wefirstneedtogetageneraloverviewofwhatthetopicisallabout.Here’saquicksnippetaboutthescienceofmagnetism.Therearetwowaystocreateamagneticfield.First,youcanwrapwirearoundanailandattachtheendsofthewiretoabatterytomakeanelectromagnet.Whenyouconnectthebatterytothewires,currentbeginstoflow,creatingamagneticfield.However,themagnetsthatsticktoyourfridgeareneithermovingnorpluggedintotheelectricaloutlet…whichleadstothesecondwaytomakeamagneticfield:byrubbinganailwithamagnettolineuptheelectronspin.Youcanessential“choreograph”thewayanelectronspinsaroundtheatomtoincreasethemagneticfieldofthematerial.


Thestrengthofamagneticfieldismeasuredin“gauss.”TheEarth’smagneticfieldmeasures0.5gauss.Typicalrefrigeratormagnetsare50gauss.Neodymiummagnets(liketheoneswe’regoingtouseinthisproject)measureat2,000gauss.Thelargestmagneticfieldshavebeenfoundarounddistantmagnetars(neutronstarswithextremelypowerfulmagneticfields),measuringat10,000,000,000,000,000gauss.(Aneutronstariswhat’sleftoverfromcertaintypesofsupernovae,andtypicallythesizeofManhattan.)

Linearaccelerators(alsoknownaslinacs)usedifferentmethodstomoveparticlestoveryhighspeeds.Onewayisthroughinduction,whichisbasicallyapulsedelectromagnet.We’regoingtouseaslowinputspeedandstrongmagnetsandmultiplythemagneticandmomentumeffecttogenerateahighoutputspeed.

Oneofthebiggestchallengeswithsuper‐strongmagnets(likeneodymium)iskeepingthemfromsmackingintoeachotherandshattering.Althoughtheserare‐earthmagnetsaresuper‐strong,theyarealsosuper‐brittle.You’llneedtobecomefamiliarwithhowtoplaceyourmagnetsonthetablesoyoudon’taccidentallyknockoneintotheother.

Whendesigningyourexperiment,you’llneedtopaycloseattentiontothefinerdetailssuchasthespacingbetweenthemagnets,sizeandshapeofthemagnets,andthesizeoftheballbearings.


Yourfirststep:DoingResearch.Whydoyouwanttodothisproject?Whatoriginallygotyouinterestedinagaussrifleorlinearaccelerator?Isittheideaofsmackingtogetherhigh‐speedobjects?Ordoesthenameoftheprojectjustsoundcool?Doyouliketheideaofputtingasmallamountofenergyintoasystemandgettingbigresults?

Takeawalktoyourlocallibrary,flipthroughmagazines,andsurfonlineforinformationyoucanfindaboutmagnetism,includinginformationabouttheelementneodymium,JamesMaxwell,electromagnetism,andwheremagnetismcomesfrom.Learnwhatotherpeoplehavealreadyfiguredoutbeforeyoustartre‐inventingthewheel!Flipopenyoursciencejournalandwritedownthingsyou’vefoundout.Yourjournalisjustforyou,sodon’tbeshyaboutjottingideasorinterestingtidbitsdown.Alsokeeptrackofwhichbooksyoufoundinteresting.You’llneedthesetitleslaterincaseyouneedtoreferbackforsomething,andalsoforyourbibliography,whichneedstohaveatleastthreesourcesthatarenotfromtheinternet.Yournextstep:Definewhatitisthatyoureallywanttodo.Inthisproject,we’regoingtowalkyoustepbystepthroughcreatingahand‐heldlinearaccelerator(orgaussrifle)madeentirelyoutofeasy‐to‐findparts.Goshoppingandgetallyourequipmenttogethernow.BeVERYcarefulwiththemagnets–don’tletthemsnaptogetherortheywillbreak!Thesemagnetsaresuper‐strong,butalsosuper‐brittle!


LinearAccelerator(GaussRifle)Experiment:MaterialsList

Beforewestartexperimenting,you’llneedtogatheritemsthatmaynotbearoundyourhouserightnow.Takeaminutetotakeinventoryofwhatyoualreadyhaveandwhatyou’llneed.

Woodorplasticrulerwithagroovedownthecenter Thickrubberbandsorstrong,super‐stickytape Foursuper‐strongmagnets(try12mmor½”neodymiummagnets)–orderonlinefromourwebsitefor

$10–we’llshowyouwheretoorder. Ninesteelballbearings(1/2”,5/8”,orothersizes)–Youcanordertheseonlinefor$4–we’llshowyou

how. Cameratodocumentproject Compositionorspiral‐boundnotebooktotakenotes Displayboard(thethree‐panelkindwithwings),about48”wideby36”tall Paperfortheprinter(andphotopaperforprintingoutyourphotosfromthecamera) Computerandprinter


LinearAcceleratorExperiment:HowtoDotheScientificMethod

Playingwiththeexperiment:It’stimetobuildyourgaussrifle.Thisshouldtakeyouanywherebetween10‐15minutes.Watchthevideoandlearnhowtobuildagaussrifle,andplaywithitabittogetthefeelforhowitworks.FormulateyourQuestionorHypothesis:You’llneedtonaildownONEquestionorstatementyouwanttotest.Becarefulwiththisexperiment‐youcaneasilyhaveseveralvariablesrunningaroundandmessingupyourdataifyou’renotcareful.Hereareafewpossiblequestions:

“Whichsizeballbearinggivesthefastestoutputspeed?” “Dorareearthmagnetsworkbetterthaniron,nickel,orcobaltmagnets?” “Doesmagnetpositionmatter?” “Whichsizesofmagnetsworkbest?” “Doesitmatterifthemagnetsarehot,warm,cold,orfrozen?” “Howmanymagnetsdoesittakeforthefinalballtoreach10feetpersecond(7mph)?” “Whatistheoptimumdistanceforthefirstballformaximumspeedonthelastball?” “Howdoestheangleoftherifleaffecttheoutputspeed?”

Onceyou’vegotyourquestion,you’llneedtoidentifythevariable.Forthequestion:“Whichinputdistancegivesthehighestoutputspeed?”,yourvariableistheamountofdistancefromthefirstballtothefirstmagnet,keepingeverythingelseconstant(spacingbetweenmagnets,typesofballs,sizeofballsandmagnets,angleoftherifle,temperatureofmagnets,etc...)Ifyouwantedtoaskthequestion:“Doesitmatterhowpowerfulthemagnetis?”yourhypothesismightbe:“Amagnettwicethesize(ormagneticstrength)willgeneratetwicetheoutputspeed.”Youcouldalsochangethedistancebetweenthemagnets.Yourhypothesismightbe:“Increasingthespacingbetweenthemagnetsincreasestheoutputspeed(ofthelastball).”Fortestingtheangleoftherifle,youcouldtryseveraldifferentangles(usingaprotractortomeasureaccurately).Youcanalsodoublethelengthofthelinacbyincreasingthenumberofmagnetstoeightinsteadoftheoriginalfour.TakingData:Anexampleofhowtorecordyourdata:Question“Whichinputdistancegivesthehighestoutputspeed?”Hypothesis:“Ithink24mmawaywillgivethefastestoutputspeed.”Here’showtorecorddata.Grabasheetofpaper,andacrossthetop,writedownyourbackgroundinformation,suchasyourname,date,timeofday,typeandsizeofmagnets(includingmagneticfieldstrengthinformation,ifyouhaveit),ballbearingtypeanddiameter,rulersize,andanythingelseyou’dneedtoknowifyouwantedtorepeatthisexperimentexactlythesamewayonadifferentday.Includeaphotographofyourinventionalso,soyou’llseeexactlywhatyourprojectlookslike.Getyourpaperreadytotakedata…andwriteacrossyourpaperthesecolumnheaders,includingthethingsin():(Note–there’sasampledatasheetfollowingthissection).

Trial# Inputdistance(distancebetweenfirstballandfirstmagnet)–theindependentvariable Outputdistance(metersorfeet)–dependentvariable Timetotravel2mor6feet(seconds)–dependentvariable Outputspeed(meter/secondorfeet/second)–acalculateddependentvariable

Besuretorunyourexperimentafewtimesbeforetakingactualdata,tobesureyou’vegoteverythingrunningsmoothly.Havesomeonesnapaphotoofyougettingreadytotest,toenterlaterontoyourdisplayboard.Placetwoparallellinesoftape


ontheground6’or2mapart,soyoucanclockthetimeittakestheballtotravelasetdistance.Youwillusethislatertocalculateyouraverageoutputspeed.Recordthefirsttrial–say,at3mm(or1”).Placeyourball3mmfromthefirstmagnet,lineuptheendoftherulerwiththetaped”startline.”Getyourstopwatchreadyandwhenyou’reset,fireaway!Clockthetimeittakesfortheballtotravel6’(or2m),andmeasurethetotaldistancetheballtraveled.Recordbothinyourdatalog.Runyourexperimentagainandagain,increasingthespacingby3mm(or1”)eachtimeforatleast8trials.Analyzeyourdata.Timetotakeahardlookatyournumbers!Whatdidyoufind?Doesyourdatasupportyouroriginalhypothesis,ornot?Makeyourselfagrid(orusegraphpaper),andplottheDistanceTraveledversustheInputDistance.Inthiscase,theInputDistancegoesonthehorizontalaxis(independentvariable),andDistanceTraveled(dependentvariable)goesontheverticalaxis.YoucanalsomakeanothergraphshowingOutputSpeed(vertical)andInputDistance(horizontal).Usingacomputer,enterinyourdataintoanExcelspreadsheetandplotascattergraph.Labelyouraxesandaddatitle.Conclusion:So‐whatdidyoufindout?Whatisthebestinputdistancetouse?Whichtypeofmagnetsgavethefurthestdistance?Doesalargermagnetgivehigherspeeds?Isitwhatyouoriginallyguessed?Scienceisoneoftheonlyfieldswherepeopleactuallythrowapartywhenstuffworksoutdifferentlythantheyexpected!Scientistsareinvestigators,andtheygetreallyexcitedwhentheygettoscratchtheirheadsandlearnsomethingnew.HotTiponBeingaCoolScientist:Oneofthebiggestmistakesyoucanevermakeistofudgeyourdatasoitmatcheswhatyouwantedtohavehappen.Don’teverbetemptedtodothis…scienceisbasedonobservationalfact.Thinkofitthisway:thelawsoftheuniversearestillworking,andit’syourchancetolearnsomethingnew!Recommendations:Thisiswhereyouneedtocomeupwithafewideasforfurtherexperimentation.Ifsomeoneelsewastotakeyourresultsanddata,andwantedtodomorewithit,whatwouldtheydo?Hereareafewspinsontheoriginalexperiment:

Varythelengthofthelinac. Changethesizeofthemagnets. Changethesizeoftheballbearings. Tryelectromagnetsinsteadofneodymium(NIB)magnets.

Makethedisplayboard.Fireupthecomputer,stickpaperintheprinter,andprintoutthestuffyouneedforyourscienceboard.Herearethehighlights:

CatchyTitle:Thisshouldencompassyourbasicquestion(orhypothesis). PurposeandIntroduction:Whystudythistopic? ResultsandAnalysis(Youcanuseyouractualdatasheetifit’sneatenough,otherwiseprintoneout.) Methods&Materials:Whatdidyouuseandhowdidyoudoit?(Printoutphotosofyouandyourexperiment.) Conclusion:Onesentencetellsall.Whatdidyoufindout? Recommendations:Forfurtherstudy. References:Whoelsehasdoneworklikethis?

Outlineyourpresentation.Peoplearegoingtowanttoseeyoudemonstrateyourproject,andyou’llneedtobepreparedtoansweranyquestionstheyhave.We’lldetailmoreofthisinthelatersectionofthisguidebook,butthemainideaistotalkaboutthedifferentsectionsofyourdisplayboardinafriendly,knowledgeablewaythatgetsyourpointacrossquicklyandeasily.Testdriveyourpresentationonfriendsandrelativesbeforehandandyou’llbesmoothlypolishedforthebigday.


LinearAcceleratorExperiment:SampleDataSheet

Gauss Rifle/Linear Accelerator

Name Size/Type of Magnet

Date Size/Type of Ball Bearing

Time Number of Magnets

Trial

#

Input

Distance Time to Travel 2m

Output

Distance

Traveled

Calculated

Average Speed

(mm) (seconds) (meters) (meters / second)

1

2

3

4

5

6

7

8

9

10


LinearAcceleratorExperiment:SampleReport

Inthisnextsection,I’vewrittenasamplereportforyoutolookoveranduseasaguide.Besuretoinsertyourownwords,data,andideasinadditiontocharts,photos,andmodels!


TitleofProject(Yourtitlecanbecatchyandclever,butmakesureitisas

descriptivelyaccurateaspossible.CenterandmakeyourtitletheLARGESTfontonthepage.)

byAuroraLipper

123MainStreet,Sacramento,CA10101

CarmelValleyGradeSchool6thgrade


TableofContentsAbstract…………………………………………………………………………………………………………………………1

Introduction………………………………………………………………………………………………………………..…2

StateofPurpose………………………………………………………………………………………………………….…3

Hypothesis…………………………………………………………………………………………………………….………5

Materials………………………………………………………………………………………………………………….……7

Procedures…………………………………………………………………………………………………………….………9

Results……………………………………………………………………………………………………………………….…12

Conclusion………………………………………………………………………………………………………….…………15

Bibliography…………………………………………………………………………………………………….……………16

Acknowledgements……………………………………………………………………………………….………………21


AbstractThisisasummaryofyourentireproject.AlwayswritethissectionLAST,asyouneedtoincludeabriefdescriptionofyourbackgroundresearch,hypothesis,materials,experimentsetupandprocedure,results,andconclusions.Keepitshort,concise,andlessthan250words.

Here’sasamplefromAurora’sreport:

Whichdropheightgeneratesthefastestbulletspeed?Afterresearchingelectromagnetism,rareearthelements,magneticfields,electronspin,induction,andferromagneticmaterials,IrealizedIhadallthebasicsformakingahand‐heldlinearaccelerator(linac).Butwhichinitialballdistancegivesthefastestoutputspeed?Ihypothesizedthatthefurtherdistancesgivethefastestspeeds.Mybestguessisthatthe24mmdropdistancewillgeneratethefastestoutputballbearingspeed.Afterfindinginexpensiveneodymium‐iron‐boron(NIB)magnetsandsteelballbearingsfromthehardwarestore,Icreatedahand‐heldlinacthatcouldfireballbearingsacrosstheroom.Irantentrialsvaryingtheinitialdropdistanceandmeasuredboththeoutputdistancetraveledandtimetotravelasetdistance(forcalculatingaveragevelocity).Ifoundthatmyinitialhypothesisofthegreatestdropdistancegeneratingthefastestoutputspeedswasinfactsupportedbythedata.Thegaussriflehadthehighestspeed(0.87meters/second)withadropdistanceof24mm.Forfurtherstudy,Irecommendrunninganexperimenttotestthevarioussizesofmagnetsandalsoanothertestforoptimumballbearingsizes.Thisexperimentwasalotoffun!


Introduction/ResearchThisiswhereallyourbackgroundresearchgoes.Whenyouinitiallywroteinyoursciencejournal,whatdidyoufindout?Writedownafewparagraphsaboutinterestingthingsyoulearnedthateventuallyleduptoyourmainhypothesis(orquestion).HereisasamplefromAurora’sreport:Therearetwowaystocreateamagneticfield.First,youcanwrapwirearoundanailandattachtheendsofthewiretoabatterytomakeanelectromagnet.Whenyouconnectthebatterytothewires,currentbeginstoflow,creatingamagneticfield.However,themagnetsthatsticktoyourfridgeareneithermovingnorpluggedintotheelectricaloutlet…whichleadstothesecondwaytomakeamagneticfield:byrubbinganailwithamagnettolineuptheelectronspin.Youcanessentially“choreograph”thewayanelectronspinsaroundtheatomtoincreasethemagneticfieldofthematerial.


Thestrengthofamagneticfieldismeasuredin“gauss”.TheEarth’smagneticfieldmeasures0.5gauss.Typicalrefrigeratormagnetsare50gauss.Neodymiummagnets(liketheoneswe’regoingtouseinthisproject)measureat2,000gauss.Thelargestmagneticfieldshavebeenfoundarounddistantmagnetars(neutronstarswithextremelypowerfulmagneticfields),measuringat10,000,000,000,000,000gauss.(Aneutronstariswhat’sleftoverfromcertaintypesofsupernovae,andtypicallythesizeofManhattan.)

Linearaccelerators(alsoknownasalinac)usedifferentmethodstomoveparticlestoveryhighspeeds.Onewayisthroughinduction,whichisbasicallyapulsedelectromagnet.I’mgoingtouseaslowinputspeedandstrongmagnetsandmultiplytheeffecttogenerateahighoutputspeed.DoesitreallymatterwhereIstarttheinputballbearingonthegaussrifle?Ifso,doesitmattermuch?


PurposeWhyareyoudoingthissciencefairprojectatall?Whatgotyouinterestedinthistopic?Howcanyouusewhatyoulearnhereinthefuture?Whyisthisimportanttoyou?

Comeupwithyourownstoryandideasaboutwhyyou’reinterestedinthistopic.Writeafewsentencestoafewparagraphsinthissection.


HypothesisThisiswhereyouwritedownyourspeculationabouttheproject–whatyouthinkwillhappenwhenyourunyourexperiment.Besuretoincludewhyyoucameupwiththiseducatedguess.Besuretowriteatleasttwofullsentences.


Ihypothesizedthatthefurtherdropdistancesgivethefastestspeeds.Mybestguessisthatthe24mmdistancebetweenthefirstballbearingandthefirstmagnetwillgeneratethefastestoutputballbearingspeed.


MaterialsWhatdidyouusetodoyourproject?Makesureyoulisteverythingyouused,evenequipmentyoumeasuredwith(rulers,stopwatch,etc.)Ifyouneedspecificamountsofmaterials,makesureyoulistthose,too!Checkwithyourschooltoseewhichunitsystemyoushoulduse.(MetricorSI=millimeters,meters,kilograms.EnglishorUS=inches,feet,pounds.)


Woodorplasticrulerwithagroovedownthecenter Thickrubberbandsorstrong,super‐stickytape Foursuper‐strongmagnets(try12mmor½”neodymiummagnets) Ninesteelballbearings(1/2”,5/8”,orothersizes) Cameratodocumentproject Compositionorspiral‐boundnotebooktotakenotes Displayboard(thethree‐panelkindwithwings),about48”wideby36”tall Paperfortheprinter(andphotopaperforprintingoutyourphotosfromthecamera) Computerandprinter


ProceduresThisistheplacetowriteahighlydetaileddescriptionofwhatyoudidtoperformyourexperiment.Writethisasifyouweretellingsomeoneelsehowtodoyourexactexperimentandreproducethesameresultsyouachieved.Ifyouthinkyou’reoverdoingthedetail,you’reprobablyjustattherightlevel.Diagrams,photos,etc.areagreataddition(NOTasubstitution)towritingyourdescription.


First,Ibecamefamiliarwiththeexperimentandsetup.Ibuiltthegaussrifleandtestedoutdifferentspacingdistancesbetweenthemagnets,gettingabetterideaofwhatIcouldexpectfromthisexperiment.OnceIwascomfortablewiththesetup,Icouldnowfocusonmyvariable(dropdistance)andhowtomeasuremyresults(speedandtime).Ifounditdifficulttomeasurethetimeittookthelastballtotravelanydistanceshorterthan2meters,soIsetthestartandfinishlinestothisminimum2meterdistance.

Imademyselfadataloggerinmysciencejournal.Iplacedtheballbearingsbetweenthemagnetsandfoundafriendtoclockthetimeforme.Idroppedthefirstballadistanceof3mmfromthefirstmagnet,clockedthedistancetotravel2meters,andwaitedfortheballtoreachastopacrossasmoothtilefloor.Imeasuredthedistanceandreadoffthetime,recordingbothinmydatasheet.Icontinuedthisprocess,increasingthedropdistanceby3mmforeachtrial.


ResultsThisisthedatayouloggedinyourScienceJournal.Includeachartorgraph–whicheversuitsyourdatathebest,orbothifthatworksforyou.Useascatterorbargraph,labeltheaxeswithunits,andtitlethegraphwithsomethingmoredescriptivethan“Yvs.XorYasafunctionofX”.Onthevertical(y‐axis)goesyourdependentvariable(theoneyourecorded),andthehorizontal(x‐axis)holdstheindependentvariable(theoneyouchanged).


Gauss Rifle/Linear Accelerator

Name

Aurora

Lipper Magnet:

Four 1/2" NIB

magnets

Date

Nov. 12,

2009 Ball Bearing:

Nine 5/8" steel ball

bearings

Time 12:09 PM

Trial

#

Input

Distance Time to Travel 2m

Output Distance

Traveled

Calculated

Average

Speed

(mm) (seconds) (meters) (m/s)

1 3 stopped at 4m 4 0.00

2 6 12.1 9.5 0.17

3 9 10.5 10.5 0.19

4 12 9.9 10 0.20

5 15 8.2 11 0.24

6 18 6.8 12 0.29

7 21 5.8 13 0.34

8 24 4.5 14 0.44

9 27 3.2 16 0.63

10 30 2.3 18 0.87

NOTE:ThenumbersaboveareNOTreal!Besuretoinputyourown.


NOTE:ThenumbersaboveareNOTreal!Besuretoinputyourown.

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

0 5 10 15 20 25 30 35

Average

Bullet Speed (m/s)

Input Distancce (mm)

Gauss Rifle Bullet Performance

0

2

4

6

8

10

12

14

16

18

20

0 5 10 15 20 25 30 35

Distance Traveled (meters)

Input Distance (mm)

Linear Accelerator Performance


ConclusionConclusionsaretheplacetostatewhatyoufound.Compareyourresultswithyourinitialhypothesisorquestion–doyourresultssupportornotsupportyourhypothesis?Avoidusingthewords“right,”“wrong”,and“prove”here.Instead,focusonwhatproblemsyouranintoaswellaswhy(orwhynot)yourdatasupported(notsupported)yourinitialhypothesis.Arethereanyplacesyoumayhavemademistakesornotdoneacarefuljob?Howcouldyouimprovethisfornexttime?Don’tbeshy–leteveryoneknowwhatyoulearned!


Ifoundthatmyinitialhypothesisofthegreatestdropdistancegeneratingthefastestoutputspeedswasinfactsupportedbythedata.Thegaussriflehadthehighestspeed(0.87meters/second)withadropdistanceof24mm.Forfurtherstudy,Irecommendrunninganexperimenttotestthevarioussizesofmagnetsandalsoanothertestforoptimumballbearingsizes.Itwasdifficulttomeasurethetimedistancebecausetherifleengagedsoquickly.Ididnothaveabsolutecontroloverthefloorconditions,andsometimestheballbearingswouldhitapieceofdirtandchangecourse.Nexttime,I’drecommendbringingabroom.


BibliographyEverysourceofinformationyoucollectedandusedforyourprojectgetslistedhere.Mostofthetime,peopleliketoseeatleastfivesourcesofinformationlisted,withamaximumoftwobeingfromtheinternet.Ifyou’reshortonsources,don’tforgettolookthroughmagazines,books,encyclopedias,journals,newsletters…andyoucanalsolistpersonalinterviews.

Here’sanexamplefromAurora’sreportonRocketry:(Thefirstfourarebookreferences,andthelastoneisajournalreference.)

Fox,McDonald,Pritchard.IntroductiontoFluidMechanics,Wiley,2005.Hickam,Homer.RocketBoys,DellPublishing,1998.Gurstelle,William.BackyardBallistics,ChicagoReviewPress,2001.Turner,Martin.RocketandSpacecraftPropulsion.SpringerPraxisBooks,2001.Eisfeld,Rainer."TheLifeofWernhervonBraun."JournalofMilitaryHistoryVol70No.4.October2006:1177‐1178.


AcknowledgementsThisisyourbigchancetothankanyoneandeveryonewhohavehelpedyouwithyoursciencefairproject.Don’tforgetaboutparents,siblings,teachers,helpers,assistants,friends…

Formattingnotesforyourreport:Keepitstraightandsimple:12pointfontinTimesNewRoman,marginssetat1”oneachside,singleor1.5spaced,labelallpageswithanumberandtotalnumberofpages(seebottomofpageforsample),andputstandardinformationintheheaderorfooteroneverypageincasethereportgetsmixedupintheshuffle(butifyoubindyourreport,youwon’tneedtoworryaboutthis).Createthetableofcontentsattheendofthereport,soyoucaninsertthecorrectpagenumberswhenyou’refinished.

Addaphotoofyourexperimentinactiontothetitlepageforadynamicfrontpage!


LinearAcceleratorExperiment:ExhibitDisplayBoard

Yourdisplayboardholdsthekeytocommunicatingyourscienceprojectquicklyandefficientlywithothers.You’llneedtofindatri‐foldcardboardorfoam‐coreboardwiththreepanelsor“wings”onbothsides.Theboard,whenoutstretched,measuresthreefeethighandfourfeetlong.Yourdisplayboardcontainsallthedifferentpartsofyourreport(research,abstract,hypothesis,experiment,results,conclusion,etc.),soit’simportanttowritethereportfirst.Onceyou’vecompletedyourreport,you’lltakethebestpartsofeachsectionandprintitoutinaformatthat’seasytoreadandunderstand.You’llneedtopresentyourinformationinawaythatpeoplecanstrollbyandnotonlygethookedintolearningmore,butcaneasilyfigureoutwhatyou’retryingtoexplain.Organizetheinformationthewaymuseumsdo,orevenmagazinesornewspapers.

HowtoWriteforyourDisplayBoardClarityandneatnessareyourtoptipstokeepinmind.Theonlyreasonforhavingaboardistocommunicateyourworkwiththerestoftheworld.Herearethesimplestepsyouneedtoknow:


Usingyourcomputer,createtextforyourboardfromyourdifferentreportsections.You’llneedtowritetextforthetitle,apurposestatement,anabstract,yourhypothesis,theprocedure,dataandresultswithcharts,graphs,analysis,andyourconclusions.Andthebestpartis‐it’sallinyourreport!Allyouneedtodoiscopythewordsandpasteintoafreshdocumentsoyoucanplaywiththeformatting.Thetitleofyourprojectstandsoutattheverytop,andcanevenhaveitsown”shingle”proppedupabovethedisplayboard.ThetitleshouldbeinTimesNewRomanorArial,atleast60ptfont...somethingstrong,bold,andeasytoreadfromacrosstheroom.Thetitlehastoaccuratelydescribeyourexperimentandgrabpeople’sattention.Herearesomeideastogetyoustarted:

GaussRifle:SmallInputSpeedYieldsBIGOutputSpeeds HandheldLinearAccelerators:StudyingtheEffectofTemperatureonInduction Linacs:JustWhereShouldYouPlacetheMagnetswithoutLosingPower? HowtoTurnMagnetsintoPower:InvestigatingtheEffectsofMagnetSpacing

Ontheleftpanelatthetop,placeyourabstractin16‐18ptfont.Underneath,postyourpurpose,followedbyyourhypothesisin24pointfont.Yourlistofmaterialsorbackgroundresearchcangoatthebottomsectionoftheleftpanel.Ifyou’recrampedforspace,putthepurposeinthecenteroftheboardunderthetitle.Inthecentralportionoftheboard,postyourtitleinlargelettering(24‐60pt.font).(Youcanalternativelymakethetitleonaseparateboardandattachtothetopofthedisplayboard…whichisgreatifyoureallywanttostandout!)Underthetitle,writeaone‐sentencedescriptionofwhatyourprojectisreallyaboutinsmallerfontsize(24‐48pt.font)Underthetitle,you’llneedtoincludehighlightsfromyourbackgroundresearch(ifyouhaven’tputitontheleftpanelalready)aswellasyourexperimentalsetupandprocedures.Usephotostohelpdescribeyourprocess.Therightpanelholdsyourresultswithprominentgraphsand/orcharts,andclearandconciseconclusions.Youcanaddtipsforfurtherstudy(recommendations)andacknowledgementsbeneaththeconclusionsinadditiontoyourname,school,andevenaphotoofyourselfdoingyourproject.Usewhitecopypaper(notglossy,oryou’llhaveaglareproblem)and18pointTimesNewRoman,Arial,orVerdanafont.Althoughthisseemsobvious,spell‐checkandgrammar‐checkeachsentence,assometimesthecomputerdoesmakemistakes!Cardstock(insteadofwhitecopypaper)won’twrinkleinareasofhighhumidity.Cutouteachdescriptionneatlyandframewithdifferentcoloredpaper(placeaslightlylargerpieceofpaperbehindthewhitepaperandglueinplace.Trimborderafterthegluehasdried.Usesmallamountsofwhiteglueorhotglueinthecornersofeachsheet,ortapetogetherwithdouble‐sidedstickytape.Beforeyougluetheframedtextdescriptionstoyourboard,arrangethemindifferentpatternstofindthebestonethatworksforyourwork.Makesuretotestoutthepositionofthetitles,photos,andtexttogetherbeforegluingintoplace!Inadditiontowords,besuretopostasmanyphotosasispleasingtotheeyeandalsohelpsgetyourpointacrosstoanaudience.Thebestphotosareofyoutakingrealdata,doingrealscience.Keepthepicturesclean,neat,andwithamattefinish.Photoslookgreatwhenborderedwithdifferentcoloredpaper(stickaslightlylargerpieceofpaperbehindthephotoforaframingeffect).Ifyouwanttoaddacaption,printthecaptiononasheetofwhitepaper,cutitout,andplaceitnearthetoporbottomedgeofthephoto,soyouraudienceclearlycantellwhichphotothecaptionbelongsto.Don’taddtextdirectlytoyourphoto(likeinPhotoshop),asphotosarerichincolor,andtextrequiresasolidcolorbackgroundforproperreading.Checkoveryourboardasyouworkandseeifyourdisplaymakesaclearstatementofyourhypothesisorquestion,thebackground(research)behindyourexperiment,theexperimentalmethoditself,andaclearandcompellingstatementofyourresults(conclusion).Selectthetextyouwritewithcare,makingsuretoaddincharts,graphics,andphotoswhereyouneedtoinordertogetyourpointacrossasefficientlyaspossible.Testdriveyourboardonunsuspectingfriendsandrelativestoseeiftheycantellyouwhatyourprojectisaboutbyjustreadingoveryourdisplayboard.


HowtoStandOutinaCrowd:Evertrytodecideonanewbrandofcereal?Whichboxdoyouchoose?Alltheboxesarecompetingforyourattention…andoutofaboutahundred,youpickone.Thisishowyourboardisgoingtolooktotherestoftheaudience–asjustoneofthecrowd.So,howdoyoustandoutandgetnoticed?First,makesureyouhaveaBIGtitle–somethingthatcanbeclearlyseenfromacrosstheroom.Usecolortoaddflairwithoutbeingtoogaudy.Picktwocolorstobeyour“colorscheme,”addingathirdforhighlights.Forexample,ablack/red/goldthemewouldlooklike:ablackcardboarddisplayboardwithtextboxesframedwithred,andatitlebarwithablackbackgroundwithredletteringhighlightedwithgold(usingtwosetsof“sticky”lettersoffsetfromeachother).Orablue/yellowschememightlooklike:royalbluefoamcoredisplayboardwithtextboxesframedwithstrongyellow.Addcolorphotographsandcolorchartsfordepth.Don’tforgetthatthewhiteinyourtextboxesisgoingtoaddtoyourcolorscheme,too,soyou’llneedtobalancethecoloroutwithafewdarkershadesasyougoalong.It’simportanttonotethatwhilestars,glitter,andsparklesmayattracttheeye,theymayalsodetractfromdisplayingthatyouareabout‘realscience’.Keepaprofessionallooktoyourdisplayasyouplaywithcolorsandshades.Ifyouaddsomethingtoyourboard,makesureit’stheretohelptheviewergetabetterfeelforyourwork.Foragaussrifleexhibit,youcanaddsparksofelectricityandmagnetsuptheedgesofyourdisplayboardandaroundthetopofyourboardingoldorblue.Addasparerifleatthetopofyourboardasanattention‐getter.Havetherifleworkingondisplaysopeoplecanseeyourexperimentinaction.Ifyou’restuckforideas,hereareafewthatyoumightbeabletouseforyourdisplayboard.Besuretocheckwithyourlocalsciencefairregulations,tobesuretheseideasareallowedonyourboard:

Yournameandphotoofyourselftakingdataonthedisplayboard Captionsthatincludethesourceforeverypictureorimage Acknowledgementsofpeoplewhohelpedyouinthelowerrightpanel Yourscientificjournalorengineer’snotebook Theexperimentalequipmentusedtotakedataanddorealscience Photoalbumofyourprogress(captionswitheachphoto)


LinearAcceleratorExperiment:OralPresentation

You’renowtheexpertoftheGaussRifleScienceExperiment…you’veresearchedthetopic,thoughtupaquestion,formulatedahypothesis,donetheexperiment,workedthroughchallenges,takendata,finalizedyourresultsintoconclusions,writtenthereport,andbuiltadisplayboardworthyofamuseumexhibit.Nowallyouneedistoprepforthequestionspeoplearegoingtoask.Therearetwomaintypesofpresentations:oneforthecasualobserver,andoneforthejudges.TheInformalTalk:Inthefirstcase,you’llneedquickandeasyanswersforthepeoplewhostrollbyandask,“What’sthisabout?”Theanswerstothesequestionsareshortandstraightforward–theydon’twantahighlydetailedexplanation,justsomethingtoappeasetheircuriosity.Rememberthatpeoplelearnnewideasquicklywhenyoucanrelateittosomethingtheyalreadyknoworhaveexperiencewith.Andifyoucandoitelegantlythroughastory,itwillcomeoffaspolishedandprofessional.TheFormalPresentation:Thesecondtalkistheoneyou’llneedtospendtimeon.Thisistheplacewhereyouneedtotalkabouteverythinginyourreportwithoutputtingthejudgestosleep.Remember,they’rehearingfromtonsofkidsalldaylong.Themoreinterestingyouare,themorememorableyou’llbe.Tips&TricksforPresentations:Besuretoincludeprofessionalism,clarity,neatness,and‘real‐ness’inyourpresentationoftheproject.Youwanttoshowthejudgeshowyoudid”real”science–youhadaquestionyouwantedanswered,youfoundoutallyoucouldaboutthetopic,youplannedaprojectaroundabasicquestion,youobservedwhathappenedandfiguredoutaconclusion.Referringbacktoyourwrittenreport,writedownthehighlightsfromeachsectionontoanindexcard.(Youshouldhaveonecardforeachsection.)What’sthemostimportantideayouwantthejudgestorealizeineachsection?Here’sanexample:ResearchCard:Whichdropheightgeneratesthefastestbulletspeed?Afterresearchingelectromagnetism,rareearthelements,magneticfields,electronspin,induction,andferromagneticmaterials,IrealizedIhadallthebasicsformakingahand‐heldlinearaccelerator(linac).Butwhichinitialballdistancegivesthefastestoutputspeed?Question/HypothesisCard:Ihypothesizedthatthefurtherdistancesgivethefastestspeeds.Mybestguessisthatthe24mmdropdistancewillgeneratethefastestoutputballbearingspeed.Procedure/ExperimentCard:Afterfindinginexpensiveneodymium‐iron‐boron(NIB)magnetsandsteelballbearingsfromthehardwarestore,Icreatedahand‐heldlinacthatcouldfireballbearingsacrosstheroom.Irantentrialsvaryingtheinitialdropdistanceandmeasuredboththeoutputdistancetraveledandtimetotravelasetdistance(forcalculatingaveragevelocity).Results/ConclusionCard:Ifoundthatmyinitialhypothesisofthegreatestdropdistancegeneratingthefastestoutputspeedswasinfactsupportedbythedata.Thegaussriflehadthehighestspeed(0.87meters/second)withadropdistanceof24mm.RecommendationsCard:Forfurtherstudy,Irecommendrunninganexperimenttotestthevarioussizesofmagnetsandalsoanothertestforoptimumballbearingsizes.Thisexperimentwasalotoffun!AcknowledgementsCard:IwanttoexpressmythankstomomforclearingoutthekitchensoIcouldhaveenoughfloorspacefortesting,tomyteacherwhoencouragesmetogofurtherthanIreallythinkIcango,tomyfriendsforhelpingchasetheballsdown,andtodadforhelpingmeunstickthemagnetswhenIknockedthemtogetheraccidentally.


TheScientificMethod

Oneoftheproblemskidshaveishowtoexperimentwiththeirgreatideaswithoutgettinglostinthejumbleofresultdata.Sooftenstudentswillnothaveanyclearideasaboutwhatchangecausedwhicheffectintheirresults!Studentsoftenhavetroublecommunicatingtheirideasinwaysthatnotonlymakesensebutarealsoacceptablebysciencefairsorothertechnicalcompetitionsdesignedtogetkidsthinkinglikearealscientist.Anotherproblemtheyfaceisstrugglingtoapplythescientificmethodtotheirscienceprojectinschool,forscoutbadges,oranyothertypeofreportwhereit’simportantthatotherfolksknowandunderstandtheirwork.

Thescientificmethodiswidelyusedbyformalscienceacademiaaswellasscientificresearchers.Formostpeople,it’sarealjumptofigureoutnotonlyhowtodoadecentproject,butalsohowtogoaboutformulatingascientificquestionandinvestigateanswersmethodicallylikearealscientist.Presentingtheresultsinameaningfulwayvia“exhibitboard”…well,that’sjustmoreofastretchthatmostkidsjustaren’treadyfor.Thereisn’tawholelotofusefulinformationavailableonhowtodoitbythepeoplewhoreallyknowhow.That’swhyI’mgoingtoshowyouhowusefulandeasyitis.

Thescientificmethodisaseriesof5stepsthatscientistsusetodotheirwork.But,honestly,youuseiteveryday,too!ThefivestepsareObservation,Hypothesis,Test,CollectData,andReportResults.Thatsoundsprettycomplicated,butdon’tworry,theyarejustbigwords.Letmetellyouwhatthesewordsmeanandhowtoplaywiththem.

Step1:Observationmeanswhatdoyousee,orhear,orsmell,orfeel?Whatisitthatyou’relookingat?Isthatwhatitusuallydoes?Isthatwhatitdidlasttime?Whatwouldhappenifyoutriedsomethingdifferentwithit?Observationisthebeginningofscientificresearch.Youhavetoseeortouchorhearsomethingbeforeyoucanstarttodostuffwithit,right?

Step2:Onceyouobservesomething,youcanthenformahypothesis.Allhypothesisreallymeansis“guess.”Ahypothesisisaneducatedguess.Tonightatdinner,whensomeoneasksyou,“Doyouwantpeasorcarrots?”Say,“IhypothesizethatIwouldlikethecarrots.”Everyonewillthinkyou’reagenius!Basicallyyou’resaying“IguessthatIwouldlikethecarrots.”Hypothesesaren’trightorwrong,theyarejustyourbestguess.

Step3:Toseeifyourguessiscorrect,youneedtodothenextstepinthescientificmethod:test.Thetestisjustwhatitsoundslike:runningexperimentstoseewhetherornotyourhypothesisiscorrect.

Step4:Asyoudoyourtests,youneedtocollectdata.Thatmeanscollectingthenumbers,themeasurements,thetimes,thedataoftheexperiment.Onceyoucollectyourdata,youcantakealookatit,orinotherwords,analyzeit.

Step5:Onceyouanalyzeyourdatayoucanreportyourresults.Thatbasicallymeanstellsomeoneaboutit.Youcanputyourdatainachartoragraphorjustshoutitfromtherooftops!

Here’sagreatwaytorememberthe5steps.Rememberthesentence“OrangeHipposTakeClassesRegularly.”Thefirstletterineachwordofthatgoofysentenceisthesameasthefirstletterineachstepofthescientificmethod.That’scalledamnemonicdevice.Makeupyourownmnemonicdevicestorememberallsortsofstuff.

“OK,sothat’swhatthewordsmean.HowdoIusethateveryday?”


Well,I’mgladyouaskedthatquestion.Ifyouhadcerealforbreakfastthismorning,youdidthescientificmethod.Onthetableyouhadabowlofcerealwithnomilkinit.Asyoulookedatyourdrycereal,youmadeanobservation,“Ineedmilk!”Atthatpoint,youmadeahypothesis,“There’smilkinthefridge.”Youcan’tbesurethere’smilkinthefridge.Someonemighthaveuseditup.Itmighthavegonebad.Aliensmayhaveusedittogasuptheirmilk‐poweredspaceship.Youjustdon’tknow!Soyouhavetodoatest.

Whatwouldbeagoodtesttoseeifthereismilkinthefridge?Openthefridge!Nowonceyoumovetheweek‐oldspaghettiandthegreenJell‐O(atleastyouhopeit’sJell‐O)outoftheway,youcanseeifthereismilkornot.Soyoucollectyourdata.Thereismilkorthereisn’tmilk.Nowyoucanfinallyreportyourresults.Ifthereismilk,youcanhappilypouritonyourcereal.Ifthereisn’tanymilk,youreportyourresultsbyshouting,“Hey,Mom...Weneedmilk!”Scientificmethod,notsohardisit?

You’llgetfamiliarwiththescientificmethodbydoingtheactivitiesandexperimentsinyourlessons.Mostscientistsdon’tusethefullversionofthescientificmethod,whichactuallyincludesseveraladditionalstepstotheonesI’veoutlinedabove.You’llfindthefull‐blownversionofthescientificmethodinthebackofthisbook.I’veincludedacopyofaspecialprojectwhichwonfirstprizeatasciencefair.You’llfindthiscompleteprojectexplainseverydetailandhowitusesthefullversionofthescientificmethodsoyoucanseehowtodoitforyourselfonanyprojectyouchoose.


VocabularyfortheUnitIfanatomhasmoreelectronsspinninginonedirectionthanintheother,thatatomhasamagneticfield.Atomsaremadeofacoregroupofneutronsandprotons,withanelectroncloudcirclingthenucleus.

Theprotonhasapositivecharge,theneutronhasnocharge(neutron,neutralgetit?)andtheelectronhasanegativecharge.Thesechargesrepelandattractoneanotherkindoflikemagnetsrepelorattract.Likechargesrepel(pushaway)oneanotherandunlikechargesattractoneanother.Generallythingsareneutrallycharged.Theyaren’tverypositiveornegative;ratherhaveabalanceofboth.

Whenelectriccurrentpassesthroughamaterial,itdoesitbyelectricalconduction.Therearedifferentkindsofconduction,suchasmetallicconduction,whereelectronsflowthroughaconductor(likemetal)andelectrolysis,wherechargedatoms(calledions)flowthroughliquids.Metalsareconductorsnotbecauseelectricitypassesthroughthem,butbecausetheycontainelectronsthatcanmove.

LEDstandsfor“LightEmittingDiode”.Adiodeislikeaone‐wayvalveforelectricity.Itletscurrentgothroughitoneway,butnottheother.Theyhavetwoleads,calledtheanodeandthecathode.

TheEarthhasahugemagneticfield.TheEarthhasaweakmagneticforce.ThemagneticfieldprobablycomesfromthemovingelectronsinthecurrentsoftheEarth’smoltencore.TheEarthhasanorthandasouthmagneticpolewhichisdifferentfromthegeographicNorthandSouthPole.

Electricityisaflowofelectrons.Aflowofelectronscreatesamagneticfield.Magneticfieldscancauseaflowofelectrons.Magneticfieldscancauseelectricity.

Electronscanhavea“left”or“right”spininadditionto‘goingaround’thenucleus.Electronstechnicallydon’torbitthecoreofanatom.Theypopinandpopoutofexistence.Electronsdotendtostayatacertaindistancefromanucleus.Thisareathattheelectrontendstostayiniscalledashell.Theelectronsmovesofastaroundtheshellthattheshellformsaballoonlikeballaroundthenucleus.

Afieldisanareaaroundanelectrical,magneticorgravitationalsourcethatwillcreateaforceonanotherelectrical,magneticorgravitationalsourcethatcomeswithinthereachofthefield.Infields,theclosersomethinggetstothesourceofthefield,thestrongertheforceofthefieldgets.Thisiscalledtheinversesquarelaw.

Magneticfieldsarecreatedbyelectronsmovinginthesamedirection.Amagneticfieldmustcomefromanorthpoleofamagnetandgotoasouthpoleofamagnet(oratomsthathaveturnedtothemagneticfield.)Ironandafewothertypesofatomswillturntoalignthemselveswiththemagneticfield.Compassesturnwiththeforceofthemagneticfield.

Ifanobjectisfilledwithatomsthathaveanabundanceofelectronsspinninginthesamedirection,andifthoseatomsarelinedupinthesamedirection,thatobjectwillhaveamagneticforce.

Magnetismiscausedbymovingelectrons.Electricityismovingelectrons.Electricitycausesmagnetism.Movingmagneticfieldscancauseelectronstomove.Electricitycanbecausedbyamovingmagneticfields.

Allmagnetshavetwopoles.Magnetsarecalleddipolarwhichmeanstheyhavetwopoles.Thetwopolesofamagnetarecallednorthandsouthpoles.Themagneticfieldcomesfromanorthpoleandgoestoasouthpole.Oppositepoleswillattractoneanother.Likepoleswillrepeloneanother.

agn etissmm - supercharged science...objectives : these are the core principles covered with this...

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