PHYSICS201FundamentalsofPhysicsIII

CourseThemes:

ElectromagneticWaves

Theory of RelativityTheoryofRelativity

QuantumMechanics

LecturesProfs.Som Tyagi andGoranKarapetrov

Recitations(section#)

LabsProf.Alexey Aprelev

Homeworksaplinglearning.com

Syllabus InfoSource

T tb k L b M lTextbook LabManual

On BB Learn

TiplerandMosca PhysicsforScientistsandEngineers (with Modern Physics)Engineers(withModernPhysics)

6thedition

(ISBN9780716789642)

Lectures and Announcements Posted: BB Learn https://learn dcollege net/LecturesandAnnouncementsPosted:BBLearnhttps://learn.dcollege.net/

HomeworkAssignments: MasteringPhysicswww.saplinglearning.com2

CourseInfoonBBLearn(learn.dcollege.netgototheLECTUREsectionofPHYS201)

1. TheRECITATIONSstartedthismorning readthematerialbeforehand2. TheLABSwillstartnextweek evensections60/62/

( ll ti t D Al A l l l @ il )(allquestionstoDr.Alexey Aprelev alexeyaprelev@gmail.com )3. ThelabdescriptionisonBBLearn(lecturesection)4. HOMEWORK:www.saplinglearning.com

C N PHYS 201 F ll 2014 T i/K tCourseName:PHYS201Fall2014Tyagi/Karapetrov

5. Officehoursandhelpsessions:myofficehours:M,W23pminDisque 622(6th floorofthis

building)goran@drexel.edu

TAhelpsessionswillbeannouncedbythePhysicsDept.(Disque 816)

5. Midterms(2)6. Lectures signupsheet,clickers

Questions?3

MidtermsMidtermsQUIZ Date/Time Rooms

I (Week-5) October 21 (8:00 8:50am) Main Aud

II (Week-7) November 4 (8:00 8:50am) Main Aud

Make-up (Week-9) November 18 (8:00 8:50am) Main Aud

Grading: The final course grade will be based on the following weights.

Two Quizzes 30 %Homework 15 %Homework 15 %Four LABS 20 %Final 35 %_____TOTAL 100 %

SyllabusRecommendationsonHowtoSucceed

ReadtheTextbook!~1hour/week,withoutead t e e tboo ! ou / ee , t outdistractions!

SummarizewhatyoureadintheTextbook(onaseparatepieceofpaper)

Comparewithclassnotes/BBLearnslides

Startdoingthehomework!

5

SeekHelp Donotwait

Dr. Goran KarapetrovOffice: Disque 622 Contact: goran@drexel.edu, tel: 215-571-4090Office hours: 2:30-3:30pm every MON and WED or by appointment

Tutoring Sessions (your TA or other TAs) 12-5pm @ Disque 919Schedule to be announced next week

6

Clickers:inputyourIDintotheclicker

YOUR Clicker ID = 11 + last 4 digits of your student ID

example:letssayyourDrexelstudentID:10089149

YOURClickerID=11+last4digitsofyourstudentID

p y y=>youwilltypein119149

Programmingtheclicker:

1. PressCh(LEDwillstartflashingredandgreen)2. Press?3. InputYOUR6digitnumber(inexampleabove119149)4. Press?(LEDturnsyellow)5. PressCh(LEDturnsgreen toindicateOK,turnsoff)

7

ElectricityandMagnetism ElectromagneticWaves

JamesClerkMaxwell(18311879)

Maxwell'sequationsMaxwell distributionMaxwelldistributionMaxwell'sdemonMaxwell'sdiscsMaxwellspeeddistributionMaxwell'stheoremMaxwellmaterial

l d ll d l

AlbertEinstein wrote:

GeneralizedMaxwellmodelDisplacementcurrentMaxwell'sWheel

ThepreciseformulationofthetimespacelawswastheworkofMaxwell.Imaginehisfeelingswhenthedifferentialequationshehadformulatedprovedtohimthatelectromagneticfieldsspread in the form of polarized waves and at the speed of light!spreadintheformofpolarizedwaves,andatthespeedoflight!

Toofewmenintheworldhassuchanexperiencebeenvouchsafed..ittookphysicistssomedecadestograspthefullsignificanceofMaxwell'sdiscovery,soboldwastheleapthathisgeniusforcedupontheconceptionsofhisfellowworkers(Science,May24,1940)

Vectorcalculus Refresher

),(function vector

),(function scalar

txE

txfr

),(div),( : vectora of divergence txEtxErrr =),(),( :scalar ofgradient txfgradtxf =r

scalar (magnitude)

vector (magnitude and direction)

)()(g

),(rot),(curl),( : vectora of (rotor) curl txEtxEtxErrrr == vector (magnitude and direction)

Important identities:

0),(curl),( :zero isgradient of curl == txfgradtxfrr

( ) ( ) 0)(ldi)(ilfdi EE rrrr ( ) ( ) 0),(curldiv),( :zero is curl a of divergence == txEtxE( ) ( ) ),(),(div),( :identity curl a of curl 2 txEtxEgradtxE rrrrrr = rrr 2Laplacian:

VectorcalculusStokesTheoremandDivergenceTheoremg

),,,(function vector

),,,(function scalar

tzyxE

tzyxfr

)()(grad afbfldfldfbb

== rrr),,,( y

ldESdESdErrrrrrr == curl

aa

LSS

SdEdVEdVErrrrr == div

SVV

ElectricityandMagnetism MaxwellsEquations

no magnetic charges(no mag monopoles)(no mag monopoles)asymmetry

asymmetry

Electric field is induced by changing magnetic field, but not vice versa???

ElectricityandMagnetism MaxwellsEquations

Lets revisit Amperes law

AmperesLaw RevisitedSame curve L

SS

Same curve L, different area S !

L

SSCurrent carrying Wire

SS

r

ISS

SdJSdB

JBrrrrr

rrr

==

00

Amperes law: J current density

I current

The magnetic field integrated around a closed curve equals the current

SthroughL

IldB 0= rr SS

qthat passes through any area bounded by this closed curve.

Since B is const at distance r and alwaysperp to dl:

IdlB 0 =L

IrB 02 = r

IB

20=

AmperesLaw Revisitednotsoobviousgeometriesg

rrL

2,10 SSthroughL

IldB =01 =+= III Sthrough

02 =SthroughI

0=L

ldBrr

L

0=B

AmperesLaw Revisitednotsoobviousgeometries CAPACITOR

LII

DoesaDCcurrentflowthroughacapacitor?

L

53%

LI

32%

15%

1. Yes

2 No 15%2. No

3. Sometimes

1 2 3

AmperesLaw Revisitednotsoobviousgeometries CAPACITOR

LI

No DC current flows through a capacitor:I

1. There are no electrons (to carry the current) in the gap

2 Current is continuous2. Current is continuous(it cant appear from a gap and sink into it)energy can not be created from nothing

Switch S has been open a long time when at t = 0, it is closed.

QUESTION: What is the time dependence ofSWSW

QUESTION: What is the time dependence ofthe current I through the capacitor ?

RRaa

VV CC

II I I

29%1. A(A) (B) (C)

63%8%2. B

3 C

1 2 3

3. C