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AAvviiaattiioonn AAccttiivviittiieess ffoorr tthhee CCllaassssrroooommForeword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

WWiinndd aanndd WWaatteerrInvestigating the Weather . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Dewpoint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Frontal Movement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6Differential Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Funnel Demonstration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Flying Beach Balls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Air Pressure Demo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Air Displaces Water. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Air Occupies Space and Has Body . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14Using the Atmosphere to Lift Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Carbon Dioxide Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

WWiinnggssInvestigating the Physics of Flight . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Hot Air Balloon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Hero’s Engine. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22Sonic Cannon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Balloon Jet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26Effervescent Rocket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30Straw Rockets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33Straw Rocket Gliders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34Answers to Questions and Thinkers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Wind, Water,andWings

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Welcome to Wind, Water, and Wings: Aviation Activities for the Classroom. The activities inthe book are designed to give students hands-on experience with weather and flight relatedphenomena.

The activities in the first half of the book are designed to help students understand the airaround them and how it impacts their daily activities, as well as flight. The activities includedin the second half of Wind, Water, and Wings bring the students in contact with aircraft thatspan the aviation time line.

The activities were chosen for their ability to engage students’ imagination, their educativequalities, and their relative low cost. They are but an introduction to the possibilities availablewith aviation related activities.

For more information about aviation education, please feel free to contact us or visit ourwebsite: www.mnaero.com/aved/publications

Best wishes in all of your educational endeavors.

The Mn/DOT Office of Aeronautics would like to express special thanks to

O.D. “Ollie” Kaldahl,University of Minnesota Workshop Director6500 Glascow Tr. S.E.Prior Lake, MN 55372-2122

and

Dr. Charley Rodriquez, Ph.D.Aviation TechnologiesSouthern Illinois UniversitySouthern Illinois AirportCarbondale, IL 62901-6816Mail Code 6816

for their assistance in developing a number of the activities presented in this book.

© 2001 Minnesota Department of Transportation, Office of Aeronautics, 222 East Plato Blvd, St. Paul, MN 55106-1618 • (651) 297-1600 • www.mnaero.com/aved

WWiinndd aanndd WWaatteerr

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WeatherWeather is a daily factor the generally affectsour lives. The weather often controls ouractivities or causes us to change our plans.While obtaining the weather forecast fromthe media has become a common part ofour routine, the weather has always playedan intregal part in aeronautical operations.The wind influences the course flown by thepilot. Temperature, humidity, and barometricpressure affect the performance of theengine and lifting surfaces of the aircraft.Storms and other forms of inclementweather may prove detrimental to the safetyof the flight.

Aviators not only concern themselves withweather conditions on the surface of theearth, they also take into consideration theweather aloft. Wind direction and speedchange as the aircraft gains altitude. Thetemperature and barometric pressure dropas the aircraft ascends. Pilots must considerthe moisture in the air when navigating. If aplane flies through clouds at high altitudes,ice may form on the exterior surface of theaircraft. Ice will change the shape of thesurface, reducing the amount of liftgenerated by the wings, and force theaircraft to descend. Visibility may be limitedby smoke, haze, pollution, and other factors.In general, accurate information concerningthe weather is paramount to aviation safety.

Several topics of discussion addressingmeteorological issues are presented in thissection. In particular, barometric pressure,temperature, humidity, and wind arehighlighted. To enhance knowledgeconcerning various aspects of weather,instructions for the construction andutilization of a select group of simpleweather instruments are included.

BarometerInstruments used to measure the weight ofthe atmosphere are called barometers. Theyrange from simple devices to elaborateinstruments. Meteorologists use barometersto report the “barometric pressure.”Changes in the barometric pressure revealshifts in the weather. Typically, low pressurefronts are associated with inclement weatherand high pressure fronts correspond withfair weather patterns.

Several classroom exercises concerningbarometers may be conducted usingcommon household items. In addition,students should be encouraged to listen tothe barometric pressure given during theweather report and note associated weatherpatterns.

Investigating the Weather

DDeewwppooiinntt

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When the dewpoint and the temperature areclose or equal, clouds or fog may form. We needa method of measurement to predict when thiswill happen. Dewpoint is the temperature atwhich water vapor condenses. This means it willbecome visible. Clouds and fog are formations ofcondensed water vapor.

In this experiment, we will learn just how thedewpoint is set. The following equipment andmaterials are required.

1. A smooth sided, shiny tin can2. A glass laboratory thermometer3. Ice cubes4. Water at room temperature

5

Fill can about three-fourths full with water. Test thewater temperature with the thermometer to besure it is at room temperature. Add three ice cubesto the water. Do this carefully so the watertemperature will lower slowly. Observe the outsideof the can. As soon as moisture starts to form,read the temperature again. This reading will bethe experimental area’s dewpoint.

1. Why is it important to know thedewpoint?

2. Can meteorologists determine theicing altitude by knowing thedewpoint?

3. Why should we use a shiny tin canfor this experiment?

THINKER 1- If the dewpoint is 48° F(9° C) and the temperature is 64° F(18° C), what is the local cloud basealtitude?(HINT: Temperature decreases 4.5° Fper 1,000 feet.)

Answers on page 36

FFrroonnttaall MMoovveemmeenntt

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We will see just how a warm front runs over a coldfront in this demonstration. We need thesematerials.

1. Rectangular Pyrex container, three by four by 10inches (7.6 x 10 x 25.4cm)

2. Sheet of heavy acetate (overhead transparencystock)

3. Food coloring (red and blue)4. Modeling clay (oil base)5. Table salt6. Flat clear glass bottle, pint or quart size

(optional)7. Heavy motor oil (optional)

modeling clay gasketpyrex container

heavy motor oil

water + blue food coloring

a cb

heavy acetate damcut to fit inside ofpyrex pan

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Cut a dam from the acetate. It should fit the insideof the Pyrex container. Now make a coil ofmodeling clay and press it around the dam. Placethe dam in the center of the container. Shape theclay gasket to fit. Press the clay firmly to the damto seal it. Check to see if the clay gasket and damcan be removed from the container in onemovement.

Now, fill the Pyrex container with water. Place thedam in the center. Add 1¼4 tsp. of salt to the wateron one side of the dam plus five or six drops ofblue food coloring and mix. Add five or six dropsof red food coloring to the clear water and mix.

After the water has settled, carefully lift the damand observe the result. You should be looking atthe side of the container.

The following experiments are optional.

1. Replace the dam in the previous experimentand mix the solution on one side of thecontainer. After the mixture has settled, removethe dam and observe the results.

2. Pour heavy motor oil into the bottle until it ishalf full. Fill the remainder of the bottle withwater that has been colored with blue foodcoloring. The water will settle to the bottom.Turn the bottle and observe the results.

1. What do the two different colors ofwater represent?

2. Why does the blue water act theway it does?

3. Why does the violet layer act theway it does?

THINKER 1- What does the action inthe tank with the red and blue watertell you about frontal activity?

Answers on page 36

DDiiffffeerreennttiiaall PPrreessssuurree

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Aircraft are machines that use various lawsof physics to achieve flight. In general, themajor force employed for mechanical flightis differential pressure. To establish adifferent pressure, at lease 2 pressures ofdifferent magnitudes are placed inopposition to each other across the surfacearea of an object. In such scenarios, theitem experiencing the differential pressureattempts to move away from the source ofhigh pressure toward the area of lowpressure. From this basic reaction desiredoutcomes are generated (e.g. airfoilsdevelop lift, propellers generate thrust, fuelflows to its discharge nozzle, etc.).

In aeronautics, the establishment of theproper amount of differential pressure isparamount to the operation of aircraft.Furthermore, the pressure differential mustbe distributed across an appropriate amountof surface area. Such requirements areevident as one evaluates the basic form ofan airplane. The shape of the wing produces

the essential pressure differential when theaircraft is at or above its minimum speednecessary for flight. The size of the wingprovides the requisite surface area neededto generate lift from the pressure differentialgenerated by the airfoil. Therefore, lift is generated by establishingand distributing a pressure differentialacross a surface.

In this unit, several examples fordemonstrating the principle of differentialpressure are presented. Many illustrationsare based on “Bernoulli’s Principle.” WhereBernoulli’s Principle involves the dynamicaction of air in motion, a number ofexperiments demonstrating differentialpressure in this section are presented usingstatic conditions.

Daniel Bernoulli (1700-1782) was a Swissscientist that studied fluid flows. From thiswork emerged “Bernoulli’s Principle.” Thislaw states that for a steady flow of fluid, thetotal energy (combination of kinetic energyfrom the velocity of the flow, the potentialenergy from elevation and gravity, and thepressure energy exerted by the fluid)remains constant along its flow route.Therefore, when velocity increases, thepressure energy of the fluid must decreaseto maintain a constant level of total energy.

In simpler terms, as velocity increases,pressure decreases.

Bernoulli’s Principle is used throughout theentire aviation industry. From the productionof lift to the workings of a carburetor, therelationship between velocity and changes inpressure is critical. As might be expected,Bernoulli’s Principle is also prevalent in otherindustries.

BBeerrnnoouullllii’’ss PPrriinncciippllee

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As previously presented, Bernoulli’s Principlestates that as the velocity of air increase, itspressure decreases. Bernoulli’s Principle maybe demonstrated by placing a ping pongball in the funnel while it is upright. Blowthrough the funnel as though you weregoing in launch the ping pong ball from thefunnel. Most people are surprised when theball remains in the funnel. In fact, blowingas hard as you can only serves to keep theball more firmly in the funnel. If you areblessed with an uncanny ability to exert a lotof wind, you can begin blowing and invert

the funnel while you blow. Surprisingly, theball remains in the funnel until you run outof breath.

What makes this demonstration work is thedifferential pressure that forms when youhave low pressure acting in the funnel andatmospheric pressure (which is higher)outside the funnel.

FFllyyiinngg BBeeaacchh BBaallll((ss))

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A common department store display may beused to demonstrate Bernoulli’s Principle.Given a fairly powerful fan and inflatedbeach ball, direct the blast from the fan sothat it is upward. Next, place the inflatedbeach ball in the moving airstream. Notehow the ball remains suspended in theairstream. Gently grab the beach ballwith both hands, and slowly pullit towards you. As the ball ispulled from the airstream,you will feel a forcetrying to pull it backinto the airflow. Thisreaction is due to thepressure differentialgenerated betweenthe surface of thebeach ball exposed tothe accelerated airflow

and the relatively stationary air outside theperimeter of the fan’s blasts. As revealed byBernoulli, the moving air mass on one sideof the ball has less pressure than thestationary air on the other side of the ball.This action produces a pressure differentialacross the ball. You can feel this force by the

tendency of the beach ball to opposebeing removed from the center of

the fan blast where it issurrounded by an area of

low pressure. Release thepartially extracted beachball and note how itdarts back into theflowing airstream.

11

Try tilting the angle of the air blast fromvertical to some other angle. If the flowgenerated by your fan is strong enough,the ball will float in midair. The reasonthis works is because of the lowpressure that surrounds the ball. Asgravity tries to pull the ball to theground, a pressure differentialexerted across the surface ofthe ball keeps it in midair.The low pressure above theball plays a majorrole insuspending theball in theatmosphere.Move the fanaround and notethat the ballfollows theairflow.

If you have apowerful fan, place twobeach balls in theairstream. Note how theybattle for the center of the airstream. As thebounce off each other, observe how theymove towards the center of the air blast onlyto bounce off each other in a repeatedfashion. Remember from the previousdemonstration using a single beach ball,when you gently and slowly pulled the ballfrom the airstream, a portion of the beachball exited the airstream and produced apressure differential that pulled the ball backto the center of the following air mass. Inthis demonstration, the two beach balls aretrying to occupy the same location as theyseek the area of low pressure.

Similar demonstrations may be performedusing a powerful blow dryer and ping pong

ball. Substituting a blow dryer for a housefan is both economical and less

bulky. However, it is difficult tosustain two ping pong balls

in the air using a hairdryer.

AAiirr PPrreessssuurree DDeemmoo

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ObjectivesThe student will observe the principles of airpressure.

Grade Level 5-8Time needed: 30 minutes

MaterialsHose from a vacuum cleaner or other flexible, wide tubing; ice cream bucket;confetti; and bird seed or tissue paper.

Procedures1. Place the confetti, bird seed, etc. in the

bucket or place a piece of tissue paper on a flat surface.

2. Hold one end of the hose just above thesubstance in the bucket or the tissuepaper.

3. Have students hypothesize what willhappen when the loose end is swung in a circle.

4. Start to swing the hose in a circle aboveyour head.

5. Have students record observations.

Principles ObservedAs the hose is swung in a circle, it creates anarea of low pressure at the end of the hoseabove your head. This low pressure areacaused the confetti to be pulled up and outof the hose. This is an example of Bernoulli’sPrinciple which states that pressure is lowerin a moving fluid.

Have students answer the question: Howdoes a vacuum cleaner work? What createsthe suction?

AAiirr DDiissppllaacceess WWaatteerr

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Almost reminiscent of the evil scientist pouringliquids from one beaker to another, thisdemonstration not only shows that air occupiesspace, but that it displaces water from aninverted cup. To conduct this experiment,partially fill an aquarium with water. Makecertain to have enough water to allow you theability to maneuver your cups without spillingwater over the top of the aquarium. Using twocups, they should be transparent and for safetyreasons made of plastic, invert one cup in theaquarium keeping it filled with air. The othercup should be initially submerged in an uprightposition to fill it with water. The water-filled cupshould then be inverted and positioned so that itis above the inverted cup filled with air. Slowlytip the air-filled glass so that the rising air entersthe inverted water-filled cup. As the air transfersinto the water cup, the liquid is displaced. By theend of the process, the cup that had the air isnow filled with water and the original water cupis filled with air. It takes a little practice to keepfrom letting the air escape from the containers.

Pour Me a Cup of Air

AAiirr OOccccuuppiieess SSppaaccee aanndd HHaass BBooddyy

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Demonstrating that air occupies space can bereadily shown by inflating a balloon or a tire,those techniques may be less obvious thansimply inverting a glass over an aquariumfilled with water and shoving the cup (pleaseuse plastic) to the bottom. To stir somecreative thinking, ask the participants howthey can send the cork to the bottom of theaquarium without touching it. The solution issimple. Capture the cork with an air-filled,inverted cup and force the cup to the bottomof the aquarium. The cork will then be restingon the bottom without being touched directlyby your action.

You may note a small amount of watertrapped within the confines of the invertedcup. A partial reason for this is due to the aircompressing inside the inverted cup as it isplaced deeper and deeper in the aquarium. Ifthe aquarium was sufficiently deep, you wouldnotice that water begins to fill the glass as itdescends. This is due to the equilibrium beingestablished between the water and the air andthe compressibility of the air.

Forcing the Cork to the Bottom

UUssiinngg tthhee AAttmmoosspphheerree ttoo LLiifftt WWaatteerr

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With a partially filled aquarium, cup, andbuoyant object, a demonstration showing howthe weight of the atmosphere can lift acolumn of water may be shown. Make certainthat the water level is near the top of theaquarium. In this experiment, challenge yourstudents or participants to devise some meansof raising the buoyant object floating on thewater so that it is above the aquarium itself.They are not allowed to scoop the floatingobject with their hands or other device.

The solution is to use atmospheric pressure.First capture the floating object with aninverted transparent cup (use plastic for safetyreasons). Next, carefully tip the cup so that theair escapes and all that is left in the invertedcup are water and the buoyant article. Lift theinverted cup and witness that the water andfloating object remain in the cup even after itsheight exceeds the uppermost surface of theaquarium. Don’t lift the rim of the invertedglass above the level of the water.

Using Atmospheric Pressure to Lift Water

CCaarrbboonn DDiiooxxiiddee DDeemmoo BBooxx

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Carbon dioxide is all around us in the air thatwe breathe. Less than 1% of our atmosphere ismade up by this compound. Carbon dioxide istasteless, odorless, invisible, does not supportcombustion and forms dry-ice whencompressed.

To show some of these properties we willconstruct a demo box out of these ninematerials.

1. A sturdy cardboard box (12" x 12" x 18")2. Six sheets of overhead transparency film3. Tape, transparent or masking4. Sharp knife or razor blade5. Small shallow metal pan6. Dry-ice7. Water8. Clear plastic drinking glass9. Small candle

Start the construction of the box by removingthe top flaps with your knife or razor blade.Turn the box over and tape all the seams tomake the bottom as airtight as possible. Nextdraw rectangles on all four sides of the boxabout 1" smaller than the transparent sheets tobe used. Place the sheets over the opening andseal in the place with the tape, making fourairtight windows in the box. We are now readyto start the demo.

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Dry-ice is extremely cold. DDOO NNOOTT TTOOUUCCHH WWIITTHH BBAARREE HHAANNDDSS!!Use only a set of tongs or heavy gloves when handling the dry-ice. Use a hammer or ice pick to break off the chunks.PPLLEEAASSEE BBEE CCAARREEFFUULL!!!!!!

CAUTION

Start by placing the small pan in the bottom ofthe box in which a small amount of water hasbeen added. Next add the dry-ice, which hasbeen broken into small chunks. At this pointlet the box and its contents rest for a shorttime while the CO2 is being generated.

We now have a box full of carbon dioxide andare ready to discover some of its properties.First, lower a lighted candle into the box.When the candle goes out we haveestablished the level of gas. Next, dip theplastic drinking glass into the box andcarefully pour the gas over a burning candle.What happened? Again, fill the glass withcarbon dioxide gas and add water. Does ittaste like carbonated water?

1. What is the temperature ofthe dry-ice?

2. What can you tell about the weight of carbon dioxide as it relates to the air around us?

3. List as many uses as you can for this gas

THINKER 1- How do you supposecarbon dioxide works in putting out a fire?

Answers on page 36

WWiinnggss

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Investigating the Physics of Flight

Important Dates in Aviation History

1783- The first recorded ascension of a hot-air balloon, built by Joseph and EntienneMontgolfier, was on June 4, in France. Threemonths later, the Montgolfiers launched ahot-air balloon for King Louis of France,carrying a duck, a rooster, and a sheep. OnNovember 21, Pilatre de Rozier and theMarquis d’Arlandes made the first mannedballoon flight, lasting 25 minutes andtraveling a little over 5 miles. On June 4,1784, Marie Thible of France became thefirst female aeronaut.

1849- In England, Sir George Cayley builtthe first successful manned glider. Heformulated the basic principles of heavier-than-air flight and turned aviation from afantasy into a science. Because of hiscontributions Sir George Cayley is called the“father of aerial navigation.”

1903- On the wind swept sand dunes ofKitty Hawk, North Carolina, Orville Wrightsuccessfully flew the first recorded powered,heavier-than-air flight in the United States. Itlasted 12 seconds and traveled 120 feet.

1927- Charles Lindbergh became the firstperson to fly solo across the Atlantic Ocean.His flight of about 3,600 miles from NewYork to Paris lasted 331¼2 hours (49 yearslater, the Concorde, traveling at Mach 2,made the same flight in 3 hours).

1944- The first production jet-poweredaircraft, the ME 262, was introduced intocombat by the Germans.

1952- The Comet, built by the de HavillandAircraft Company, became the firstcommercial jet airplane.

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1954- Two Comets, one in January and onein April, exploded in flight on clear days. Allwere grounded, and for the next yearextensive research was conducted to solvethe mystery. The conclusion: they were notbuilt to stand the pressure changes thatoccur when the plane rapidly climbs anddescends to its normal flight level.

1958- The Boeing Company watched andlearned from the Comet experience androlled out their first commercial jet, the 707,ushering in the jet age for commercialtravel.

1957- The Soviet Union launched Sputnik,the first artificial satellite to orbit the earth.

1961- Russian Yuri Gagarian became thefirst person to orbit the earth in space.

1969- American Neil Armstrong became thefirst person to walk on the moon.

Today- The space shuttle orbits 250 milesabove the earth, traveling at 17,500 mph,and it takes just 90 minutes to complete atrip around the world.

HHoott AAiirr BBaalllloooonn

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A good introduction to this project is talkingabout the hot air balloons students haveseen and how they work. There are also alot of good books on the subject. For fifth andsixth graders, Hot Air Henry, by MaryCalhoun, is a good one to read first.

Materials (for one 5ft. Balloon)1. Six panels of jewelers’ tissue, dimensions

below (Jewelers’ tissue is 20" wide, so youdon’t have to piece it together. Ifunavailable, glueing regular tissue papertogether will work).

2. Markers.3. Elmer’s glue or 4-5 gluesticks.4. Hot air popcorn popper or hair dryer may

be used for the five foot balloon. The ninefoot pattern requires a commercial hot airballoon launcher. They are available fromcompanies such as PITSCO, use propane,are safe, and cost around $80.

5. A place to launch - a gym is best. Thecooler the room, the better. Outdoors, acalm day and an open field away frompower lines and traffic are needed. Acommercial launcher removes thedifficult-ies involved when using anextension cord for the hair dryer/popcornpopper.

6. Rubber bands.7. String.

Procedure1. Create a tagboard template for students

to use to trace the shape of the panelsonto the tissue (pattern information is onthe next page). Students can trace and cuttheir own panels, or panels can be cutand ready to decorate for youngerstudents.

2. Students can work in small groups todesign and color their panels. It is helpfulto avoid letters and numbers becausewhen the panels are put together, somemay be backwards. They only have tocolor one side because the markers bleedthrough. Put newsprint under the panelsbefore coloring.

3. The six panels go together like anaccordion. First lay one down and put acontinuous thin line of glue along theentire left side. Younger children could useglue sticks. It’s very important that theglue line does not stop and start, whichmakes a hole for air to escape.

4. Put another panel right on top. Now youhave the left side glued together. Put athick glue line along the right side of thispanel.

5. Lay another panel on top. Put the thinglue line on the left side. Continue layingpanels on top and putting glue onalternate sides till the six panels are all onthe pile. Glue the two open sides together.

6. To seal the top, tie the string or threadabout two inches down. Leave the bottomopen.

7. To launch, hold bottom down over hot airpopper/hair dryer or launcher and let theballoon inflate. It’ll feel hot and starttugging. At that point, take the bottom,squish it together, wrap the rubber bandaround it, and let it go quickly. An adultshould do most of the holding becausethese appliances become very hot (withthe exception of the commercial launcher)

courtesy Sharon Lovell

21

and could cause burns. If you’re inside,the balloon will rise and stay up until theair inside it has a temperature (andweight) equal to the room air. If the roomis cool, it will stay up longer. The studentscan time how long it’s up. They can talkabout variables, comparing results if theballoon is launched at different times ofthe day when the room is warmer ofcooler, or if the length of time theballoon is heated makes a difference.

Five foot balloon pattern

For a nine foot balloon, use ten 9 foot panels.

(Requires commercial launcher)

hair dryer

HHeerroo’’ss EEnnggiinnee

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Historical BackgroundHero of Alexandria conducted many experimentsrelated to hot air, steam and mechanics. All of his workwas done before 300 AD, which is quite remarkableviewing the technical nature of his inventions. TheAeolipile, pictured here, is a kind of steam turbine. Thetubes fixed to a hollow sphere had ends bent over inopposite directions. The sphere was mounted over aboiler; steam passed into it through the hollowbearings; resulting in the steam escaping through thetubes, under pressure, causing the sphere to rotate.

Classroom ApplicationA model of Hero’s engine can be used quitesuccessfully in the classroom to demonstrate anumber of different principles. The three that canbe best related to aerospace would be; Newton’sthird Law of Motion; the power of steam underpressure; and the principle of a rocket or jetengine. All of these demonstrations relate to the action/reaction principle and can be used to assist the students memory ofthese truths.

Necessary Construction Materials1. One Copper tank float2. Short eye bolt (1¼4" x 20, 3¼4" long)3. Two 1¼8" copper tubing, 2" long4. One medium fishing swivel5. A short piece of cord6. Tools: soldering equipment and an awl

Exercise extreme care in using the torch and avoid eye contactwith the resulting steam, both of these elements are very hot andcan cause serious burns!PPLLEEAASSEE BBEE CCAARREEFFUULL!!!!!!

CAUTION

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ConstructionStart by bending soft 90 degree bends in both 1¼8"copper tubes. Next, using the awl, punch twoholes about 1¼8" above the center seam of thefloat and 180 degrees away from each other.Make these holes so that the copper tubes fit verytight and position them as shown in the diagram.With the tubes in place solder them carefully sothat no steam can escape around them. Screw inthe eye bolt, connect the fishing swivel and tie onthe cord. Your Hero Engine is ready to use.

Demonstration ProcedureSet the engine in a stand, as illustrated below. Fillthe engine with about 10 to 12 cc’s of waterthrough one of the copper jets using a largesyringe. Place a heat source under the float untilsteam starts to escape from the jets. (Probably thebest heat source is a propane torch as the RPM’scan be charged by moving the torch to or awayfrom the float.)

SSoonniicc CCaannnnoonn

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We can hear sounds and sometimes feel theirpower. In this experiment, we will work with thepower of sound waves. To show their strength, wewill construct a cannon that “shoots” sound. Wehave two alternatives for construction.

(A)1. A cardboard mailing tube 21¼2" (6.4cm)

in diameter and about 18" (45.7cm) long2. Two index cards3. White glue4. One candle

or (B)1. Two Pringles Potato chip canisters2. Two rubber bands3. Two large paper clips4. A 3¼8" nut5. Tape6. One candle

glue fillet

diameter (one-half inch)

diameter of mailing tubeindex card

detail of lid

clip inside lid

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A. Draw a circle with the same diameter as themailing tube on each of two index cards. On onecard, cut a concentric circle 1¼2" (1.25 cm) indiameter inside the larger one. Place a heavy coatof glue on both ends of the tube and press thecircles against the glue. When it dries, trim off theexcess index cards. (Be sure the cards are gluedsecurely to the mailing tube.)

B. Remove bottom metal rim of the first canister.On this canister punch two holes just below toprim, opposite each other. Tie ends of rubberbands to 3¼8" nut. Attach paperclips inside thetube to other ends of rubber bands. Replaceplastic lid under rubber bands, making sure nut isoutside. On the second canister punch 1¼2" hole inthe center of bottom. Remove top metal rim. Placecanisters, open ends together. Seal with tape tocomplete.

We now have a sonic cannon. We will use aburning candle to demonstrate the cannon’spower. Place the flame about 12" (30.5cm) awayfrom the hole of the cannon. Snap the solid end ofthe cannon with your finger or draw back nut andrelease, (with a little practice, you will be able toput out the flame with a snap.) Change thedistance between the candle and the cannon andrepeat the experiment. How far can you get awayfrom the candle and still put it out?

1. Do the air molecules and the soundwaves move at the same speed?

2. Why is the small hole necessary?

THINKER 1- What do you supposethe shape of the invisible sound waveis?

Answers on page 36

BBaalllloooonn JJeett

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Principles ObservedSir Isaac Newton’s Third Law of Motionstates that for every action there is an equaland opposite reaction. A jet engine uses this principle by taking in air, a gas, on one side,energizing it by compression and rapidexpansion, and using that energy to create areaction, namely thrust out the oppositeside. The balloon is simulating the idea ofcompression and thrust, or rapid expansion.This experiment also shows the efficiency ajet engine has by channeling all reactiveenergy in one pointed direction.

Materials needed1. Long party balloons (the type that can be

used to make balloon animals).2. A balloon pump (approximate $4.00).3. Fishing line (thin, thread-like line works

better than thicker, blue translucent line).4. Tape.5. Small straw or swissel stick.6. Balloon jet pattern (see pages 28 & 29).

This experiment will deal mainly with thethrust created by compressing a gas andletting it expand out of a smaller area.

Procedure1. Color and cut out the stabilizers, wings,

nose cone, and jet body.2. Bend and tape the jet body into a tube

shape. Having a 11¼2" plastic pipe towrap the body around will make this taskeasier.

3. After bending on the dotted lines, tapethe stabilizers and wings to the jet body.

4. Curl and tape the nose cone so it is thesame size as the jet body. If it is largerthan the jet body, it will rub against thefishing line and reduce performance.

5. Run fishing line through a small stirringstraw (swissel stick) and attach each endof the line to a chair.

6. Attach the jet body to the straw withcellophane tape, make sure the fishingline runs between the stabilizers and willnot get caught on the nose cone.

The Balloon Jet project was inspired by an idea in The Berenstain Bears FLY-IT! Up, Up, andAway book by Stan & Jan Berenstain.

ObjectiveThe students will be able to demonstrate and describe how a jet engine works while workingwith the concept of thrust and compression. Have students note that a jet engine is dividedinto three main parts:

A: The Compressors.B: The Combustion Chambers.C: The Turbines.

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7. Inflate and insert a balloon into the jetbody, pinching the opening of the balloonclosed with your fingers. The jet will workmost effectively if the balloon is not bentto one side. Balloons are flexible enoughto be gently straightened.

8. Release the balloon.

Extension Ideas1. Have the students experiment with different sizes or types of balloons, jets and straws.

Make a chart recording the effects of the different variables.2. Move the string from a horizontal to a vertical position. Which jet goes the highest?

What forces are working against the jet?3. Use the energy from the balloon to power free-flying aircraft which the students could

design and build.4. Discuss the concepts of energy, potential energy, and equilibrium in balloons.5. Allow students to attach a small piece of straw to the mouth of the balloon to create a

smaller hole (See diagram). The smaller hole will result in a greater amount of thrustbecause of the compressed gas escaping from a smaller hole.

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Stabilizers

Wings

Cut on solid linesFold on dotted lines

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DescriptionStudents construct a rocket powered by thepressure generated from an effervescentantacid tablet reacting with water. The rocketliftoff is a good example of Newton’s Lawsof Motion.

Materials1. Paper.2. Plastic 35mm Fugi film canister* (the

canister must have an internal-sealinglid).

3. Cellophane tape.4. Scissors.5. Effervescent antacid tablet.6. Paper towels.7. Water.8. Eye protection.9. Optional: Rocket pattern (see page 32).

ProcedureFor best results, students should work inpairs. It will take approximately 40 to 45minutes to complete the activity. Makesamples of rockets in various stages ofcompletion available for students to study.This will help some students visualize theconstruction steps.

A single sheet of paper is sufficient to makea rocket. Be sure to tell the students to planhow they are going to use the paper. Let thestudent decide whether to cut the paper theshort or long direction to make the bodytube of the rocket. This will lead to rockets ofdifferent lengths for flight comparison. Oryou can use the pattern.

Make sure students tape the film canister tothe rocket body, mount the canister with thelid end down, and extend the canister farenough from the paper tube to makesnapping the lid easy. Some students mayhave difficulty in forming the cone. To make

a cone, cut out one-fourth of the circle andcurl it into a cone. Cones can be any size.

Background InformationThis activity is a simple but excitingdemonstration of Newton’s Laws of Motion.The rocket lifts off because it is acted uponby an unbalanced force (First Law). This isthe force produced when the lid blows off bythe gas formed in the canister. The rockettravels upward with the force that is equaland opposite to the downward forcepropelling the water, gas, and lid (ThirdLaw). The amount of force is directlyproportional to the mass of water and gasexpelled from the canister and how fast itaccelerates (Second Law).

Discussion1. Does the amount of water placed in the

cylinder affect how high the rocket will fly?If so, why?

2. Does the temperature of the water affecthow high the rocket will fly? If so, why?

3. Does the amount of the tablet used affecthow high the rocket will fly? If so, why?

4. Does the length or empty weight of therocket affect how high the rocket will fly?If so, why?

5. How would it be possible to create a two-stage rocket?

courtesy NASA

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AssessmentAsk students to explain how Newton’s Lawsof Motion apply to this rocket. Compare therockets for skill in construction. Rockets thatuse excessive paper and tape are likely to beless efficient flyers because they carryadditional weight.

Extensions1. Hold an altitude contest to see which

rockets fly the highest. Launch the rocketsnear a wall in a room with a high ceiling.Tape a tape measure to the wall. Let allstudents take turns measuring rocketaltitudes.

2. Experiment with adding different liquidsat different temperatures with theeffervescent tablet, i.e. carbonated water,vinegar, or soda.

3. What geometric shapes are present in arocket?

4. Use the discussion questions to designexperiments with the rockets. Graph yourresults.

* Film canisters are available from camerashops and stores where photographicprocessing takes place. These businessesrecycle the canisters and are often willingto donate them for educational use. Besure to obtain canisters with the internalsealing lid. These are usually whitecanisters. Canisters with the external lid(lid that wraps around the canister rim)will not work. These are usually blackcanisters.

32

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Materials1. Pair of Scissors.2. 1 Roll of Scotch Tape.3. Drinking Straws of different diameters.4. Markers or Crayons.5. Pattern.

Instructions1. Cut the 3 Wings following the dark lines.2. Color the Wings.3. Using two 1" pieces of tape, tape each wing

about 1" from the back of the straw.4. Wrap a 3" piece of tape around the front end

of the straw so the opening is taped shut.5. Place the smaller diameter straw into the

Straw Glider and blow into the smaller straw.6. If front of glider rises, wrap some more tape

near the front of the glider until the gliderflies level. If the front of rocket sinks, wrapsome tape around the straw just behind thewings.

courtesy Jerry Brenden

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Materials1. Pair of Scissors.2. Roll of Scotch Tape.3. Drinking Straws of different diameters.4. Markers or Crayons.5. Glider pattern (see page 35).

Instructions1. Cut the Wing, Horizontal Stabilizer, and

Vertical Stabilizer following the dark lines.2. Color the Wing, Horizontal Stabilizer, and

Vertical Stabilizers.3. Fold the Wing and Horizontal Stabilizer

along the dotted lines.4. Using two 2 to 3" pieces of tape, attach the

wing to the middle of the larger diameterstraw.

5. Using a 2" piece of tape, attach theHorizontal Stabilizer towards the back of thestraw.

6. Using two 2" pieces of tape, attach theVertical Stabilizer above the HorizontalStabilizer.

7. Wrap a 3" piece of tape around the frontend of the straw so the opening is tapedshut.

8. Place the smaller diameter straw into theStraw Glider and blow into the smallerstraw.

If the front of glider rises, wrap some moretape near the front of the glider until the gliderflies level. If front of glider sinks, wrap some tape around the straw just in front of theHorizontal Stabilizer.

courtesy Jerry Brenden

35

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CCaarrbboonn DDiiooxxiiddee1. -95° F.2. It is heavier than the air around us.3. Inflation of life rafts, fire extinguishers, compressed into dry ice, etc.4. Displaces the oxygen.

SSoonniicc CCaannnnoonn1. No. Sound waves collide with air molecules and do not move them,

they cause them to vibrate.2. To let the sound waves escape in a precise direction.

Thinker 1 -

FFrroonnttaall MMoovveemmeenntt1. Warm and cold air masses.2. Represents the cold air which is more dense (with the salt).3. Because it is less dense than the blue water mixture.4. Violet (mixture of the red and blue) is half the density of the blue

colored water.Thinker 1 - Warm air masses over-ride cold air masses.

DDeewwppooiinntt1. When dewpoint and temperature are the same, low laying clouds

are formed, commonly referred to as fog.2. Yes. Temperature is lower than freezing. At this point the water vapor

in a cloud will form ice on the wings.3. A dull surfaced can will not show condensation as well as a shinny

can. A can with ridges will not permit an even distribution ofcondensation.

Thinker 1 - 3,700 feet above mean sea level (MSL).