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TABLEOFCONTENTSIntroduction...............................................................................................................................................................................................................3

EducationalGoalsfortheEnergySeries........................................................................................................................................................4

MasterMaterialsListforAllLabs.....................................................................................................................................................................6

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

Lesson#1:Cansolarenergybeconcentrated?...........................................................................................................................................8

Lesson#2:SolarBattery....................................................................................................................................................................................10

Lesson#3:SolarDrinkingBird.......................................................................................................................................................................13

Lesson#4:Canwindbeusedasasourceofenergy?............................................................................................................................16

Lesson#5:WindTurbine...................................................................................................................................................................................19

Lesson#6:Canwaterbeusedtostoreenergy?.......................................................................................................................................21

Lesson#7:Firewaterballoon.........................................................................................................................................................................24

Lesson#8:Balloongymnastics.......................................................................................................................................................................27

Lesson#9:Ghostcoin..........................................................................................................................................................................................29

Lesson#10:What’saJoule?..............................................................................................................................................................................32

Lesson#11:MeasuringPower........................................................................................................................................................................34

Lesson#12:Steamboats.....................................................................................................................................................................................36

Lesson#13:StirlingEngine..............................................................................................................................................................................39

Lesson#14:PeanutEnergy...............................................................................................................................................................................44

Part2Evaluation...................................................................................................................................................................................................48

Part2Quiz................................................................................................................................................................................................................49

Part2LabPractical...............................................................................................................................................................................................51

AnswerstoExercises...........................................................................................................................................................................................52

VocabularyfortheUnit.......................................................................................................................................................................................55


Introduction

Greetings,andwelcometothestudyofEnergy.Thisunitwascreatedbyamechanicalengineer,universityinstructor,airplanepilot,astronomer,robot‐builderandrealrocketscientist…me!IhavethehappyopportunitytoteachyoueverythingIknowaboutenergyoverthenextsetoflessons.Ipromisetogiveyoumybeststuffsoyoucantakeitandrunwithit…orfly!

Togetthemostoutoftheselabs,therearereallyonlyacoupleofthingstokeepinmind.Sinceweareallheretohavefunandlearnsomethingnew,thisshouldn’tbetoohard.

Oneofthebestthingsyoucandoasthestudentistocultivatetheircuriosityaboutthings.Whydidthatmove?Howdidthatspin?What’sreallygoingonhere?

ThisunitonEnergyischockfullofdemonstrationsandexperimentsfortwobigreasons.First,they’refun.Butmoreimportantly,thereasonwedoexperimentsinscienceistohoneyourobservationalskills.ScienceexperimentsreallyspeakforthemselvesmuchbetterthanIcaneverputintowordsorshowyouonavideo.AndI’mgoingtohityouwithalotofthesesciencedemonstrationsandexperimentstohelpyoudevelopyourobservingtechniques.

Scientistsnotonlylearntoobservewhat’sgoingonintheexperiment,buttheyalsolearnhowtoobservewhattheirexperimentistellingthem,whichisfoundbylookingatyourdata.It’snotenoughtoinventsomenewkindofexperimentifyoudon’tknowhowitwillperformwhentheconditionschangeabit,likeonMars.We’regoingtolearnhowtopredictwhatwethinkwillhappen,designexperimentsthatwilltestthisidea,andlookovertheresultswegottofigureoutwheretogofromthere.Scienceisaprocess,it’sawayofthinking,andwe’regoingtogetplentyofpracticeatit.

GoodluckwiththisEnergyunit!


FortheParent/Teacher:EducationalGoalsfortheEnergySeries

Energyisthemoverandshakeroftheuniverse.Heatfromthesun,soundsfromyourradio,ridingabikeandwatchingamovieareallexpressionsofdifferentformsofenergy.Asyousittherereadingthis,thereisenergyflowingallaroundyouintheformoflightwaves,soundwaves,radiowaves,heatandmore.Youareconstantlybeingbombardedbyenergy.Energyiseverywhere,allthetime.

We’regoingtofocusondifferentformsofenergysuchaskineticandpotentialenergy,howsimplemachines(pulleys,levers,andpendulums)makeenergyintousableforms,andinvestigateseveralmethodsoffinding,converting,storingandusingalternativeenergy.

Herearethescientificconcepts:

Energycanbecarriedfromoneplacetoanotherbyheatflow,orbywavesincludingwaterwaves,lightandsound,orbymovingobjects.

Whenfuelisconsumed,mostoftheenergyreleasedbecomesheatenergy. Heatflowsinsolidsbyconduction(whichinvolvesnoflowofmatter)andinfluidsbyconductionandalso

byconvection(whichinvolvesflowofmatter). Heatenergyisalsotransferredbetweenobjectsbyradiation;radiationcantravelthroughspace. ThesunisthemajorsourceofenergyforphenomenaontheEarth'ssurface,poweringwinds,ocean

currents,andthewatercycle. SolarenergyreachesEarththroughradiation,mostlyintheformofvisiblelight. HeatfromEarth'sinteriorreachesthesurfaceprimarilythroughconvection. Convectioncurrentsdistributeheatintheatmosphereandoceans. Differencesinpressure,heat,airmovement,andhumidityresultinchangesofweather. Theutilityofenergysourcesisdeterminedbyfactorsthatareinvolvedinconvertingthesesourcesto

usefulformsandtheconsequencesoftheconversionprocess. Considerdifferentnaturalenergyandmaterialresources,includingair,soil,rocks,minerals,petroleum,

freshwater,wildlife,andforests,andclassifythemasrenewableornonrenewable. Studythenaturaloriginofthematerialsusedtomakecommonobjects.

Bytheendofthelabsinthisunit,studentswillbeableto:

Designandbuildexperimentsthatdemonstratethatsourcesofstoredenergytakemanyforms,suchasfood,fuel,andbatteries.

KnowhowtodemonstratehowsolarenergyreachesEarththroughradiation,mostlyintheformofvisiblelight.

Understandhowtodeterminethatenergycanbecarriedfromoneplacetoanotherbywaves,suchaswaterwavesandsound,byelectriccurrent,andbymovingobjects.

Differentiateobservationfrominference(interpretation)andknowscientists’explanationscomepartlyfromwhattheyobserveandpartlyfromhowtheyinterprettheirobservations.

Measureandestimatetheweight,lengthandvolumeofobjects.


Formulateandjustifypredictionsbasedoncause‐and‐effectrelationships. Conductmultipletrialstotestapredictionanddrawconclusionsabouttherelationshipsbetween

predictionsandresults. Constructandinterpretgraphsfrommeasurements.

Followasetofwritteninstructionsforascientificinvestigation.


MasterMaterialsListforAllLabs

Thisisabrieflistofthematerialsthatyouwillneedtodoalloftheactivities,experimentsandprojectsinthisunit.Thesetofmaterialslistedbelowisjustforonelabgroup.Ifyouhaveaclassof10labgroups,you’llneedtoget10setsofthematerialslistedbelow.Mostmaterialsarereusable.

(RS=RadioShack)

alligatorclipleads(RS#278‐1156) bi‐polarLED(RS#276‐012) blackspraypaint CDs(3oldones) coin copperflashingsheet(½sq.foot) drillwith1/16″bit drinkingbird electricfan electricstove(notgas) electricaltape electricalwire(3‐conductorsolidwire) fishingline(15lb.testorsimilar) foamblock(about6”long) hairdryer holepunch lampwithanincandescentbulb largeplastic2Lsodabottle lightweightstring(about4feetlong) magnifyinglens multimeter(RadioShack#22‐810) nylonbushing(fromhardwarestore) oldinnertubefromabikewheel packofsteelwool

paperclips papercups permanentmarker pinwheel(canbepurchasedormadefrom

constructionpaper) plasticstraw(longerthanthewidthofthe

shoebox) pliers propeller pushpin razor salt(1/4cup) sandpaper sheetmetalshears silverorwhitespraypaint smallcandleoralcoholburner smallshoebox(children’ssize) superglue Swissarmyknife(withcanopeneroption) tape threesodacans watchorclock wirecutters

©2014SuperchargedScience Page7 www.SuperchargedScience.com

LabSafetyGoggles:Theseshouldbewornwhenworkingwithchemicals,heat,fire,orprojectiles.Theseprotectyoureyesfromchemicalsplatter,explosions,andtinyfast‐movingobjectsaimedattheeyes.Ifyouwearglasses,youcanfindgogglesthatfitoverthem.Don’tsubstituteeyeglassesforgoggles,becauseofthelackofsideprotection.Eyeglassesdon’tprovidethisimportantsideeyeprotection.

CleanupMesses:Yourlabareashouldbeneat,organized,andspotlessbeforeyoustart,duringyourexperiment,andwhenyouleave.Scientistswastemoretimehuntingforlostpapers,piecesofanexperiment,andtryingtorepositionsensitiveequipment…allofwhichcouldhaveeasilybeenavoidedhadtheybeentaughtorganizationalskillsfromthestart.

DisposeofPoisons:Ifapoisonoussubstancewasused,created,orproducedduringyourexperiment,youmustfollowtheproperhandlingproceduresfordisposal.You’llfinddetailsforthisintheexperimentsasneeded.

SpecialNotesonBatteries:Donotusealkalinebatterieswithyourexperiments.Findthesuper‐cheapkindofbatteries(usuallylabeled“HeavyDuty”or“SuperHeavyDuty”)becausethesetypesofbatterieshaveacarbon‐zinccore,whichdoesnotcontaintheacidthatalkalinebatterieshave.Thismeanswhenyouwireupcircuitsincorrectly(whichyoushouldexpecttodobecauseyouarelearning),thecircuitswillnotoverheatorleak.Ifyouusealkalinebatteries(likeEnergizerandDuracell)andyourstudentsshortacircuit,theirwiresandcomponentswillgetsuper‐hotandleakacid,whichisverydangerous.

NoEatingorDrinkingintheLab:Allfoodsanddrinksarebannedfromyourclassroomduringscienceexperimentation.Whenyoueatordrink,youruntheveryrealriskofingestingpartofyourexperiment.Forelectricityandmagnetismlabs,alwayswashyourhandsafterthelabisovertorinseofftheleadfromtheelectricalcomponents.

NoHorsePlay:Whenyougoofaround,accidentshappen,whichmeanschemicalsspill,circuitsshort,andallkindsofhazardscanoccurthatyouweren’texpecting.Neverthrowanythingtoanotherpersonandbecarefulwhereyouputyourhands–itcouldbeinthemiddleofasensitiveexperiment,especiallywithmagnetismandelectricity.Youdon’twanttoruntheriskofgettingshockedorelectrifiedwhenit’snotpartofyourexperiment.

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

Questions:Ifyou’renotsureaboutsomethingstopandask,nomatterwhatit’sabout.Ifyoudon’tknowhowtoproperlyhandleachemical,dopartofanexperiment,ask!Ifyou’renotcomfortabledoingpartoftheexperiment,thendon’tdoit.


Lesson#1:Cansolarenergybeconcentrated?

Overview:Todayyou’lluseaplainoldlightbulbtolearnmoreaboutthespecialwaysthatthesun’senergyisusedandharnessed,andespeciallytheimplicationsthatithasonourenergyneeds.

WhattoLearn:Thisexperimentwillteachyouhowthesun’sraysinteractwithourplanet,andhowinturnweusethisenergyinanumberofways.

Materials

Lampwithanincandescentbulb Magnifyinglens

LabTime

1. Theresultsofthisexperimentmaybeeasiesttoobserveifdoneatnightinadarkroom.Askanadulttoremovethelampshadefromalampthatusesasingleincandescentbulb.Anincandescentbulbisthetypethatgetsquitehotwhenused.Turnonthelamp.Turnoffalltheotherlightsintheroom.

2. Standabouttwofeetfromthewallthatisthegreatestdistancefromthelamp.Thereshouldbenothingbetweenyouandthelampbulb.Placethemagnifyingglassonthewallsothatthelensisflatagainstthewall.Now,slowlymovethelensawayfromthewallandtowardthelight.Keepthelensparalleltothesurfaceofthewall.Asyoumovethelensoutward,watchthewall.

3. Recordyourobservationsontheworksheet.

ConcentratedSolarObservations:

Describeordrawtheimageonthewallinthespacebelow:

Howbrightisthisimage?Howbig?

Whathappenswhenyoumovethelens?Thebulb?Whyisthishappening?


TheUnitedStatesDepartmentofEnergy’sNationalRenewableEnergyLaboratoryinColoradousessolarenergytooperateaspecialfurnace.Thishigh‐temperaturesolarfurnaceusesalenstoconcentratesunlight.Aheliostat(adeviceusedtotrackthemotionofthesunacrossthesky)isusedsothattheimagereflectedfromamirrorisalwaysdirectedatthesamespot.Thelensisusedtoconcentratesunlightfromamirrortoanareaaboutthesizeofapenny.Thisconcentratedsunlighthastheenergyof20,000sunsshininginonespot.

Inlessthanhalfasecond,thetemperaturecanberaisedto1,720°C(3,128°F),whichishotenoughtomeltsand.Thishigh‐temperaturesolarfurnaceisbeingusedtohardensteelandtomakeceramicmaterialsthatmustbeheatedtoextremelyhightemperatures.

Concentratedsunlightalsohasbeenusedtopurifypollutedgroundwater.Theultravioletradiationinsunlightcanbreakdownorganicpollutantsintocarbondioxide,water,andharmlesschlorineions.ThisprocedurehasbeensuccessfullycarriedoutattheLawrenceLivermoreLaboratoryinCalifornia.Inthelaboratory,upto100,000gallonsofcontaminatedwatercouldbetreatedinoneday.

Thecurvedshapeofthemagnifyinglensweusedinthisexperimentcauseslightraystobendandfocusonanimage.Whenwelookthroughthelens,wecanuseittomakewritingorsomeotherobjectappearlarger.However,themagnifyinglenscanalsobeusedtomakesomethingsmaller.Thelightfromthebulbisbentandfocusedonthewallwhenthelensisheldfarfromthelampandclosetothewall.Theimageismuchbrighterthanthesurroundings.Thisisbecauseallthelightfallingonthesurfaceofthelensisconcentratedintoamuchsmallerarea.

Whensunlightisconcentratedbypassingitthroughalens,theresultcanbeanintenselybrightandhotspotoflight.Evenasmallmagnifyingglasscanincreasetheintensityofthesunenoughtosetwoodandpaperonfire.Weareusingalightbulbratherthansunlightforthisexperimentbecauseconcentratedsunlightcanbeveryharmfultoyoureyes.NEVERLOOKATACONCENTRATEDIMAGEOFTHESUN.

Doyouknowofanycommonwaysthatsolarenergycanbeconcentratedforouruse?Whataboutheatinghomes?Evencoolinghomesinhotterclimates?Providingelectricity?Didyouknowthatsolarenergycanevenbeusedtobreakdownpollutantstocleanwater?Anyothers?

ExercisesAnswerthequestionsbelow:

1. Namethreeusesforsolarenergy:a. b. c.

2. Whattypeofheatenergyistransmittedbythesun?a. Conductionb. Convectionc. Plasmad. Radiation

3. Circlethefollowingphenomenainfluencedbythesun:a. Pressureb. Climatec. Weatherd. Wind


Lesson#2:SolarBattery

Overview:Thisisafavoriteexperimentofmine,sinceitreallydemonstratesthephotoelectriceffectinausefulway.Here’sthedeal:electronscanbeeitherfreeorattachedtotheatom,andwhenyouhitametalplacewithUVlight,someoftheattachedelectronsbreakfreeandstartcurrentflowinginacircuit.

WhattoLearn:Thislessonwillhelpyoulearnhowsolarenergyreachestheearthintheformofradiationandtakesmultipleforms,mostlyvisiblelight.

Materials

½sq.footofcopperflashingsheet(checkthescrapbinatahardwarestore) Alligatorclipleads(RS#278‐1156) Multimeter(RadioShack#22‐810) Electricstove(notgas) Largeplastic2Lsodabottle ¼cupsalt Sandpaper&sheetmetalshears

LabTime

1. First,we’llpreparethecopper.Usethemetalshearstocutthesheetsothatitfitsontopoftheelectricburner.Becareful,theedgeswillbesharp!

2. Washthesheetverycarefullywithsoapandwateronbothsides.Onceit’sdry,usethesandpapertoscruboffanylooseparticles.Takeyourtimeandscrubitalloveronbothsides.

3. Placethecopperontheburnerandturnittothehighestsetting.Leaveitforaboutahalfhour.Watchthecopperforthefirstfewminutes.Whatdoyounotice?

4. Youcanprepareyourwaterbottlewhilethesheetiscooking.Cuttheneckoffthebottle.5. Aftercooking,turnofftheburnerandallowthecoppertocoolontheburnerforanothertwenty

minutes.Itwillshrinkandyoushouldnoticeablacklayerwhichmayflakeoff.Wewantthelayerunderneaththeblacklayer.Washthecoppertoremoveanylargerblackpieces.

6. Cutthesheetintwo,andthenbendthesheetsothatitcanfitintothebottle.Wewantthesmoothestsidetofaceoutward.Takeafresh,uncookedpieceofcopperandplaceitinside.It’simportantthatthetwosheetsdon’ttouch.

7. Takesomesaltandpouritinthere.Pourwaterintothebottle,leavingaboutaninchofairinthetopofthebottle.Stiritupwithaspoonsothatthesaltandwaterformasolution.

8. Turnonyourmultimeter,andattachthepositivesidetotheuncookedsideofcopper,andthenegativetothecookedsideofcopper.Setthemetertoreadamps.

9. Readthemeterinbothsunlightandshade.Whatdoyounotice?Recordyourdataintheworksheet.


SolarBatteryData

Location MultimeterReading (Amps)

FullSunlight

Shade

Partialsunlight

Weareusingthephotoelectriceffectforthisexperiment.ThiscuprousoxidesolarcellejectselectronswhenplacedinUVlight–andsunlighthasenoughUVlighttomakethissolarcellwork.Thosefreeelectronsarenowfreetoflow–whichisexactlywhatwe’remeasuringwiththevoltmeter.

Semiconductorsarethesecrettomakingsolarcells.Asemiconductorisamaterialthatispartconductor,partinsulator,meaningthatelectricitycanflowfreelyornot,dependingonhowyoustructureit.Therearelotsofdifferentkindsofsemiconductors,includingcopperandsilicon.

Insemiconductors,there’sagap(calledthebandgap)that’slikeagiantchasmbetweenthefreeelectrons(electronsthathavebeenknockedoutofitsshell)andboundelectrons(electronsstillattachedtotheatom).Electronscanbeeitherfreeorattached,butitcostsacertainamountofenergytogoeitherway(kindoflikeatollbooth).

Whensunlighthitsthesemiconductormaterialinthesolarcell,someoftheelectronsgetenoughenergytojumpthegapandgetknockedoutoftheirshelltobecomefreeelectrons.Thefreeelectronszipthroughthematerialandcreateaflowofelectrons.Whenthesungoesdown,there’snosourceofenergyforelectronstogetknockedoutoforbit,sotheystayputuntilsunrise.

Reading

Solarenergyisthekindofenergymostpeoplethinkofwhenyoumention”alternativeenergy,”andforgoodreason!Withoutthesun,noneofanythingyouseearoundyoucouldbehere.Plantshaveknownforeverhowtotaketheenergyandturnitintousablestuff…sowhycan’twe?

Thetruthisthatwecan.Whilenormallyittakesfactoriesthesizeofacityblocktomakeasiliconsolarcell,we’llbemakingacoppersolarcellafteraquicktriptothehardwarestore.We’regoingtomodifythecopperintoaformthatwillallowittoreactwithsunlightthesamewaysilicondoes.Theimageshownhereisthetypeofcopperwe’regoingtomakeonthestovetop.

Thissolarcellisarealbattery,andyou’llfindthateveninadarkroomyou’llbeabletomeasureatinyamountofcurrent.However,eveninbrightsunlight,you’dneed80millionofthesetolightaregularincandescentbulb.



1. Thesunlightcausestheelectronstoflowfromthecuprousoxidebecauseof:a. Photosynthesisb. Theelectromagneticspectrumc. Thephotoelectriceffectd. Thephotochemicalprinciple

2. Whatmaterialdomostsolarcellsuseinsteadofcopper?

3. Whatpartoftheelectromagneticspectrumismostactiveinthisexperiment?a. VisibleLightb. UltravioletLightc. GammaRaysd. Microwaves

4. Whenyoureadamps,youread:a. Currentb. Voltagec. PowerDrawd. Work


Lesson#3:SolarDrinkingBird

Overview:Thedrinkingbirdisaclassicsciencetoythatdipsitsheadupanddownintoaglassofwater.It’sfilledwithaliquidcalledmethylenechloride,andtheheadiscoveredwithredfeltthatgetswetwhenitdrinks.Buthowdoesitwork?Isitperpetualmotion?We’lltakealookatwhat’sgoingonwiththebird,whyitworks,andhowwe’regoingtomodifyitsoitcanrunonitsownwithoutusinganywateratall!

WhattoLearn:You’lllearnmoreaboutthesunthanaboutthebirditself,andespeciallyaboutthesun’sinfluenceontheEarth,air,andwater.

Materials

drinkingbird silverorwhitespraypaint blackspraypaint razor mugofhotwater sunlightorincandescentlight

LabTime

1. Takethebirdoutofitsholder,andcarefullyremovethetailfeather,hat,andfeltsection.Removeanygluewithascraperorhotwater,whichwillallowthegluetoloosenandeasilypeeloff.Becarefulnottoholdthebirdbythehead,becauseitishollowandcanbreakifyougriptootightly!

2. Paintthetop(withthepeak,fromwhichthehatwasremoved)eitherwhiteorsilver.Paintthebottomblack.Allowittodry.

3. Whenthepaintisdry,reattachthebirdtoitsstand,andplaceitinthesun.Adjustthefasteningbanduntilthebirdissecure,ifneeded.

4. Liquidisbeingheatednowinthebird,sothebirdwillbegintippingaswaterbeginsmovingfromthebottomtothetop.Thebottomofthebirdisnowblack,andblackabsorbsmoreenergyandheatsupthetailofthebird.Sincethetailsectioniswarmer,thepressuregoesupandtheliquidgetspushedupthetube.Bycoveringtheheadwithwhite(orsilver)paint,youarereflectingmostoftheenergysoitremainscool.RememberthatwhitesurfacesactlikemirrorstoIRlight(whichiswhatheatenergyis).


Observations

1. Whatishappeningtoyourdrinkingbird?

2. Doesitworkbetterwithhotorcoldwater?

3. Doesitworkinanenclosedspace,suchasaninvertedaquarium?

4. Onarainydayordry?

5. Inthefridgeoronaheatingpad?

Reading

Thedrinkingbirdinthisexperimentisanexampleofaheatengine.Theliquid’sspecialpropertiesallowthemotiontocontinue,solongasthereissomewaterprovidedtothesystem.

What’ssospecialabouttheliquid?Methylenechlorideismadeofcarbon,hydrogen,andchlorineatoms.It’sbarelyliquidatroomtemperature,havingaboilingpointof103.5°F,soitevaporatesquiteeasily.Itdoeshaveahighvaporpressure(6.7psi),meaningthatthemoleculesontheliquidsurfaceleave(evaporate)andraisethepressureuntiltheamountofmoleculesevaporatingisequaltotheamountbeingshovedbackintheliquid(condensed)byitsownpressure.(Forcomparison,thevaporpressureofwaterisonly0.4psi.)

Thebirdneedsatemperaturedifferencebetweentheheadandtail.Sincewaterneedsheatinordertoevaporate,theheadcoolsasthewaterevaporates.Thistemperaturedecreaselowersthepressureinsidethehead,pushingliquiduptheinnertube.Withmoreliquid(weightinthehead),thebirdtipsover.Thebirdwetsitsownheadtostartthiscycleagain.

Thetricktomakingthisworkisthatwhenthebirdistippedover,thevaporfromthebottommovesupthetubetoequalizethepressureinbothsides,orhe’dstayputwithhisheadinthecup.Sadly,thisisn’tperpetualmotionbecauseassoonasyoutakeawaythewater,thecyclestops.Italsostopsifyouenclosethebirdinajarsowatercannolongerevaporateafterawhile.Doyouthinkthisbirdcanworkinarainstorm?InAntarctica?

Vaporpressurecanalsochangewithtemperaturechanges.Thevaporpressuregoesupwhenthetemperaturegoesup.Sincethewetheadiscoolerthanthetail,thevaporpressureatthetopislessthanatthebottom,whichpushestheliquidupthetube.SoitreallydoesmatterwhetherthebirdisoperatinginArizonaortheAmazon.Thebirdwilldipmoretimesperminuteinadesertthanarainforest!Thisisbecauseevaporationwillworkmorequicklyinthedesert.



1. Wheredoesmostoftheenergyonearthcomefrom?a. Undergroundb. Thesunc. Theoceans

2. Whatisonewaythatweuseenergyfromthesun?

3. Whatistheprocessbywhichtheliquidisbeingheatedinsidethebird?a. Precipitationb. Pressurec. Evaporationd. Transpiration


Lesson#4:Canwindbeusedasasourceofenergy?

Overview:Constructyourownwindmillanduseittocollectpaperclipsunderitsownpower.Intheprocessyou’lllearnimportantconceptsaboutalternativeenergyandthegrowingimportanceofrenewableresourceslikewindpower.

WhattoLearn:Payattentiontohowthesunallowswindtoform,andtheimportanceofwindinourfuture’senergyneedsandconsumption.

Materials

Pinwheel(canbepurchasedormadefromconstructionpaper) Paperclips Tape Smallshoebox(children’ssize) Electricfan Lightweightstring(about4feetlong) Plasticstraw(longerthanthewidthoftheshoebox) Holepunch

LabTime

1. Useaholepunchtopunchholesintheoppositesidesacrossthewidthofthecardboardshoebox.Usethenarrowsidesoftheboxsothetwoholesarelessthan6inches(15centimeters)apart.Makesuretheholesaredirectlyoppositeeachother.Placeaplasticstrawthroughtheholes.Enlargetheholesifyouneedto.

2. Usethebladesfromapinwheelorcutandfoldasquarepieceofconstructionpaperintotheshapeofapinwheel.Attachthebladestooneendofthestraw.

3. Partiallyunfoldasmallpaperclipandinsertitintothelargerendofthestraw.Pushthestraightenedendofthepaperclipthroughthecenterofthepinwheel.Bendthisendofthepaperclipandtapeittotheoutsideofthepinwheel.

4. Setthefanonatableorcountertop.Holdtheshoeboxsothatthepinwheelisfreetoturn.Haveanadultpluginandturnonthefan.Movethewindmillboxtodirectthebreezefromthefantowardthebladesofthepinwheel.Movetheboxuntilyoufindthebestangleofthefantothepinwheelsothatthebladesturnfreely.

5. Turnoffthefan.Tapeoneendofthestringtothesideofthestrawwithnopinwheeljustoutsidethebox,andwrapthestringaroundthestrawafewtimes.Tietheotherendofthestringtoapaperclip.Attachfiveotherpaperclipstothepapercliptiedtothestring.Allowthestringtohangdownsothatthepaperclipsontheendofthestringrestonthefloor.

6. Now,youwilltesttoseeifyourwindmillcanconvertwindpowertodoworkandliftthepaperclipsofftheground.Turnonthefanandholdtheboxwhereyoudidbeforetomakethepinwheelturn.Recordallyourobservationsanddataintheworksheet.


WindEnergyObservations

1. Doesthewindmillturnthestraw?

2. Doesthestringwraparoundthestrawasthestrawturns?

3. Whathappenstothepaperclips?

4. Howisenergybeingconvertedbyyourwindmill?

Reading

Onewaytostoretheenergyproducedbyawindmillistoliftaweight.Whentheweightisallowedtofall,workcanbeproduced.Weightsinagrandfatherclockareusedtostoreenergyandcanrunaclockforaweekorlonger.Awindmill’senergycanbeusedtopumpwatertoastorageareaatahigherelevation.Later,thiswatercanbeallowedtofallthroughaturbinewhichturnsageneratorandproduceselectricity.

Electricitycanalsobeproduceddirectlyfromwindpower.Theshaft,orrodtowhichthewindmillbladesareattached,canbeusedtoturnagenerator.Ageneratorordynamoisusedtoconvertmechanicalenergyintoelectricalenergy.Powerconversionunitscanchangethedirectcurrentthatwindgeneratestoanalternatingcurrent.Thealternatingcurrentcanbefeddirectlyintoutilitylinesandusedinourhomes.

Thesunistheoriginalsourceofwindpower.Withoutthesuntoheattheearth,therewouldbenowind.Theenergyofthesunheatstheearth,butallpartsoftheeartharenotatthesametemperature.Thesedifferencesintemperatureareresponsibleforglobalandlocalpatternsofwind.Forexample,duringthedayaconstantwindblowsfromtheseatowardthelandalongcoastalregions.Airabovethehotterlandrisesandcooler,heavierairabovetheoceanmovesintotakeitsplace.

Thepowerofthewindcanbeharnessedtodowork.Thewindhasbeenusedtomovesailingships.Thewindhasenoughpowertomoveshipsacrossoceansandaroundtheworld.Windmillshavebeenusedforpumpingwaterandturningstonestogrindgrain.MillionsofwindmillshavebeenusedontheplainsofAmerica,Africa,andAustraliatopumpwaterfromdeepwellsforlivestockandhumans.

Inthiscentury,windmillsorwindengineshavebeenusedtogenerateelectricity.Morethan15,000windengineswereinstalledinCaliforniainthe1980s.Thesewindengineshavethecapabilitytoproduceupto1.5billionwattsofelectricity.InCaliforniain1987,windwasusedtoproduceasmuchelectricityasthecityofSanFranciscousesinanentireyear.


TheUnitedStateshaslargereservesofcoal,naturalgas,andcrudeoil(whichisusedtomakegasoline).However,theUnitedStatesusestheenergyofmillionsofbarrelsofcrudeoileveryday,anditmustimportabouthalfitscrudeoilfromothercountries.

Burningfossilfuels(oil,coal,gasoline,andnaturalgas)producescarbondioxidegas.Carbondioxideisoneofthemaingreenhousegasesthatmaycontributetoglobalwarming.Inaddition,burningcoalandgasolinecanproducepollutionmoleculesthatcontributetosmogandacidrain.

Usingrenewableenergy‐‐suchassolar,wind,water,biomass,andgeothermal‐‐couldhelpreducepollution,preventglobalwarming,anddecreaseacidrain.Nuclearenergyalsohastheseadvantages,butitrequiresstoringradioactivewastesgeneratedbynuclearpowerplants.Currently,renewableenergyproducesonlyasmallpartoftheenergyneedsoftheUnitedStates.However,astechnologyimproves,renewableenergyshouldbecomelessexpensiveandmorecommon.

Hydropower(waterpower)istheleastexpensivewaytoproduceelectricity.Thesuncauseswatertoevaporate.Theevaporatedwaterfallstotheearthasrainorsnowandfillslakes.Hydropoweruseswaterstoredinlakesbehinddams.Aswaterflowsthroughadam,thefallingwaterturnsturbinesthatrungeneratorstoproduceelectricity.

Currently,geothermalenergy(heatinsidetheearth),biomass(energyfromplants),solarenergy(lightfromconcentratedsunlight),andwindarebeingusedtogenerateelectricity.Forexample,inCaliforniatherearemorethan16,000windturbinesthatgenerateenoughpowertosupplyacitythesizeofSanFranciscowithelectricity.

Inadditiontoproducingmoreenergy,wecanalsohelpmeetourenergyneedsthroughconservation.Conservationmeansusinglessenergyandusingitmoreefficiently.


1. Namethreesourcesofrenewableenergy:a. b. c.

2. Whatdoesthesunhavetodowithwind?

3. Namethreeexamplesofwindpowerinhistoricalorcurrentusage:

a. b. c.


Lesson#5:WindTurbine

Overview:We’lltakealookatpropellerdesignaswebuildaworkingwindturbine.

WhattoLearn:Weuseallkindsofresourcestomeetourenergyneeds.You’lllearnhowwindenergyissoimportant,andtheprinciplesbehindhowenergyisconvertedsothatwecanuseit.

Materials

AdigitalMultimeter(RadioShack#22‐810) Alligatorclipleads(RS#278‐1156) 1.5‐3VDCMotor(RS#273‐223) 9‐18VDCMotor(RS#273‐256) Bi‐polarLED(RS#276‐012) Foamblock(about6”long) Scrappieceofwoodformounting PropellerfromoldtoyorcheapfanorRadioShackSolarKit277‐1201. Sharpknifeorscissors Hairdrier Hotgluegun

LabTime

1. Slicethefoamblockinhalflengthwise.Adultsupervisionisneeded!Stackthetwopiecesandhotgluethemtogether.

2. Mountyourblocksonapieceofwoodorsturdypaper.Next,attachyourmotortothetopofthefoam.Makesuretheshaftisoverhangingtheedge,becausewewanttoattachapropeller.

3. Attachthepropellertotheshaftofthemotor,andmakesureitisabletospinfreely.4. Mountthesolarcellontoyourbase,andwirethemotorintotheappropriateplacesonthesolarcell.5. Gooutsideandgivethecellatest,makingsurethepropellerspinsaccordingtotheamountofsunlight.6. Disconnectthewiresandsetthesolarcellaside.TakeyourLEDsandspreadtheirmetalwiressothat

youcanstickthemintothefoamblockbelowyourpropeller.7. Takealligatorclipsandattachthemtothewiresofthemotor.Makesuretheclipsareattachedtothe

wiresthemselves,nottheinsulation.8. Weneedtofigureoutifthewiresareconnectedproperly.Useahairdryeronthelowestheatsetting,

highestpower,tospinthepropeller.Experimenttofindthesweetspotwherethepropellerwillspinwell.IfyourLEDsdonotlightup,tryusingthehairdryerontheoppositeside,behindthemotor.Doesitwork?Ifnot,thenreversethewires.

9. DisconnectthealligatorclipsfromtheLEDsandattachthemultimetertothemotor.Clickthedialthreetimestothelefttogettherightrangeofvoltage.Usethehairdryeragainandrecordyourreadingfromthemultimeteronyourworksheet.Whataboutifyouarrangethedryertoblowfromtheotherside?


WindTurbineDataTable

WindDirectionorConfiguration Reading(Voltage)

Frontofpropeller

Rearofpropeller

Believeitornot,mostoftheelectricityyouusecomesfrommovingmagnetsaroundcoilsofwire!Windturbinesspinbigcoilsofwirearoundverypowerfulmagnets(orverypowerfulmagnetsaroundbigcoilsofwire)bycapturingtheflow.

Here’showitworks:Whenapropellerisplacedinamovingfluid(likethewaterfromyoursinkorwindfromyourhairdryer),thepropellerturns.Ifyouattachthepropellertoamotorshaft,themotorwillrotate.Ithascoilsofwireandmagnetsinside.Thefastertheshaftturns,themorethemagnetscreateanelectricalcurrent.

Theelectricitytopoweryourcomputer,yourlights,yourairconditioning,yourradioorwhatevercomesfromspinningmagnetsorwires!

Reading

Windpowerisarecentlyburgeoningsourceofrenewableenergy.Althoughwe’veinvestedinlarge‐scalewindpowerinNorthAmericaforthepastfortyyears,recentprojectsinnorthernandcentralEuropehaveconstructedthemostmassivearraysyetseen.IntheNorthSea,massivefloatingturbinesgenerateenoughelectricitytopowerthousandsofhomes.Althoughlegalandenvironmentalchallengesrestricthowmuchwecanbuildwindfarms(theyarequiteahazardtomigratingbirdpopulations,andevenhaveeffectsonlivestockandhumansettlementsnearthem),theywillprovideanimportantpartofourfutureenergyneeds.


1. Trueorfalse:Electricityinawindturbineiscreatedbymagnetsintheturbine:a. Trueb. False

2. Whatisoneadvantageofusingwindforelectricity?

3. Whatmightbeoneproblemwithconstructingwindfarmstomeetallourenergyneeds?


Lesson#6:Canwaterbeusedtostoreenergy?

Overview:Oursuncanbeusedforallkindsofthings.Inourworldthatissufferingfromanenergycrisis,weneedtobemoreproactivetoaddresstheseneeds.Didyouknowthatlargebodiesofwaterareusedtostoreheat?Findouthowtoday!

WhattoLearn:Thislabwillallowustoseehowwaterinteractswiththeheatenergyofthesun.Rememberthekeytermswe’velearnedsofar:conduction,convection,etc.Whattypeofheattransferdoweobservehere?

Materials

Papercups Measuringcups Hotwater Watchorclock Sink Refrigerator(withfreezercompartment) Thermometer

LabTime

1. Turnonthehotwaterfaucetandwaituntilthewaterishot.Becarefulnottoburnyourself!2. Add¼cupofhotwatertothefirstpapercup,and1cupwatertothesecondpapercup.3. Placebothcupsinthefreezercompartmentoftherefrigerator.Besuretolabelyourcups!4. Checkthewaterafter30minutes.Recordyourdataintheworksheet,takingthetemperatureofeachcup

andseeingifthewaterhasfrozen.5. Returntothefreezerandcheckthetemperatureagainafter45minutes.Recordyourdata.6. Keepcheckingthecupsatfifteen‐minuteintervalsuntilonehasfrozen.Recordyourdatainthesheet.

WaterEnergyDataTable

Time(minutes) Temperature(Cup1) Temperature(Cup2) Frozen?(Cup1) Frozen?(Cup2)

0

30

45

60

75


1. Whatconclusionscanyoudrawabouttherelationshipbetweenthewater’samountanditsabilitytostoreenergy?Howdoyouknow?

Reading

Thesun’sraysinteractwiththeearthinanumberofdifferentways,andscientistsaregettingmorecreativeintheirattemptstoharnesstheabundantenergythatcomesdowntoinfluencethesurface.Solarpondsarelargebodiesofwaterthatcanstoreheatduringthedaytimeandreleaseitduringtheeveningtobeusedbysomenearbyarea.Theyinvolveplacingalayeroffreshwateratopsaltwater,whichremainsheavierandsinkstothebottom.Thefreshwaterinsulatesthebottomlayerofwaterandcanretainquiteabitofheat.

Inafreshwaterpond,asthewateronthebottomisheatedbysunlight,thehotwaterbecomeslighterandrisestothetopofthepond.Thisconvectionormovementofhotwatertothetoptendstocarryawayexcessheat.However,inasaltwaterpond,thereisnoconvectionsoheatistrapped.InIsraelaseriesofsaltwater,solarpondsweredevelopedaroundtheDeadSea.Theheatstoredinthesesolarpondshasbeenusedtorunturbinesandgenerateelectricity.

Foranotherexampleofwaterstoringlargeamountsofheatenergy,considerthecityofSanFrancisco.Itliesattheendofapeninsula,surroundedonthreesidesbywater.Ifyou’veevervisitedthecityduringthesummer,you’llbesurprisedbyhowcolditcanget!Thisisbecausethewaterabsorbsalargeamountoftheenergyfromthesun,leavingthelandmasscolderthanthecontinentalinland.ThisiswhythecityofOaklandacrossthebaycanbeexperiencingcompletelydifferentweatherjustafewmilesaway.

Temperatureisameasureoftheaveragehotnessofanobject.Thehotteranobject,thehigheritstemperature.Asthetemperatureisraised,theatomsandmoleculesinanobjectmovefaster.Themoleculesinhotwatermovefasterthanthemoleculesincoldwater.Rememberthattheheatenergystoredinanobjectdependsonboththetemperatureandtheamountofthesubstance.Asmalleramountofwaterwillhavelessheatenergythanalargeramountofwateratthesametemperature.

Increasingthetemperatureofalargebodyofwaterisonewaytostoreheatenergyforlateruse.Alargecontainerfilledwithsaltwater,calledbrine,maybeusedtoabsorbheatenergyduringthedaywhenitiswarm.Thisenergywillbeheldinthesaltwateruntilthenightwhenitiscooler.Thisstoredheatenergycanbereleasedatnighttowarmahouseorbuilding.Thisisonewaytostorethesun’sheatenergyuntilitisneeded.



1. Whattypeofheattransferisatworkinasolarpond?a. Kineticb. Conductionc. Potentiald. Convectione. Radiation

2. Whatunitsdoweusetomeasureenergy?a. Kilowattsb. Joulesc. Newtonsd. Kilowatt‐hours

3. Drawadiagramofasolarpondinthespacebelow:


Lesson#7:Firewaterballoon

Overview:Heatenergycanbeobservedinmanyways.Thissimpleexperimentallowsustoseehowheatistransferred.

WhattoLearn:We’reexploringhowheatenergycanmovebetweenobjectsinavarietyofways.

Materials

Balloon Water Matches,candle,andadulthelp Sink

LabTime

1. Puttheballoonunderthefaucetandfilltheballoonwithsomewater.2. Nowblowuptheballoonandtieit,leavingthewaterintheballoon.Youshouldhaveaninflated

balloonwithatablespoonortwoofwateratthebottomofit.3. Carefullylightthematchorcandleandholditunderthepartoftheballoonwherethereiswater.4. Feelfreetoholditthereforacoupleofseconds.Youmightwanttodothisoverasinkoroutsidejustin

case!5. Recordobservationsintheworksheetbelow

Fire‐WaterBalloonObservations

1. Whatdidthewaterdototheheatofthematch?

2. Whydidn’ttheballoonpop?Whatdoesthistellyouaboutheatenergyinthissystem?


Sowhydidn’ttheballoonpop?Thewaterabsorbedtheheat!Thewateractuallyabsorbedtheheatcomingfromthematchsothattherubberoftheballooncouldn’theatupenoughtomeltandpoptheballoon.Waterisverygoodatabsorbingheatwithoutincreasingintemperature,whichiswhyitisusedincarradiatorsandnuclearpowerplants.Wheneversomeonewantstokeepsomethingfromgettingtoohot,theywilloftenusewatertoabsorbtheheat.

Thinkofadrysponge.Nowimagineputtingthatspongeunderaslowlyrunningfaucet.Thespongewouldcontinuetofillwithwateruntilitreachedacertainpointandthenwaterstartedtodripfromit.Youcouldsaythatthespongehadawatercapacity.Itcouldonlyholdsomuchwaterbeforeitcouldn’tholdanymoreandthewaterstarteddrippingout.Heatcapacityissimilar.Heatcapacityishowmuchheatanobjectcanabsorbbeforeitincreasesintemperature.Thisisalsoreferredtoasspecificheat.Specificheatishowmuchheatenergyamassofamaterialmustabsorbbeforeitincreases1°C.

Reading

Ifyou’veeverhadashot,youknowhowcoldyourarmfeelswhenthenurseswipesitwithapadofalcohol.Whathappenedthere?Well,alcoholisaliquidwithafairlylowboilingpoint.Inotherwords,itgoesfromliquidtogasatafairlylowtemperature.Theheatfromyourbodyismorethanenoughtomakethealcoholevaporate.

Asthealcoholwentfromliquidtogas,itsuckedheatoutofyourbody.Forthingstoevaporate,theymustsuckinheatfromtheirsurroundingstochangestate.Asthealcoholevaporated,youfeltcoldwherethealcoholwas.Thisisbecausethealcoholwassuckingtheheatenergyoutofthatpartofyourbody(heatwasbeingtransferredbyconduction)andcausingthatpartofyourbodytodecreaseintemperature.

Asthingscondense(gofromgastoliquidstate)theoppositehappens.Thingsreleaseheatastheychangetoaliquidstate.Thewatergasthatcondensesonyourmirroractuallyincreasesthetemperatureofthatmirror.Thisiswhysteamcanbequitedangerous.Notonlyisithottobeginwith,butifitcondensesonyourskinitreleasesevenmoreheatwhichcangiveyousevereburns.Objectsabsorbheatwhentheymeltandevaporate/boil.Objectsreleaseheatwhentheyfreezeandcondense.

DoyourememberwhenIsaidthatheatandtemperaturearetwodifferentthings?Heatisenergy–itisthermalenergy.Itcanbetransferredfromoneobjecttoanotherbyconduction,convection,andradiation.We’renowgoingtoexploreheatcapacityandspecificheat.

Waterisverygoodatabsorbingheatwithoutincreasingintemperature,whichiswhyitisusedincarradiatorsandnuclearpowerplants.Wheneversomeonewantstokeepsomethingfromgettingtoohot,theywilloftenusewatertoabsorbtheheat.

Thinkofadrysponge.Nowimagineputtingthatspongeunderaslowlyrunningfaucet.Thespongewouldcontinuetofillwithwateruntilitreachedacertainpointandthenwaterstartedtodripfromit.Youcouldsaythatthespongehadawatercapacity.Itcouldonlyholdsomuchwaterbeforeitcouldn’tholdanymoreandthewaterstarteddrippingout.Heatcapacityissimilar.Heatcapacityishowmuchheatanobjectcanabsorbbeforeitincreasesintemperature.Thisisalsoreferredtoasspecificheat.Specificheatishowmuchheatenergyamassofamaterialmustabsorbbeforeitincreases1°C.



1. Whatisspecificheat?a. Thespecificamountofheatanyobjectcanholdb. Theamountofenergyrequiredtoraisethetemperatureofanobjectby1degreeCelsius.c. Thetypeofheatenergyanobjectemitsd. Thespeedofacompound’smoleculesatroomtemperature

2. Nametwotypesofheatenergy:

3. Whattype(ortypes)ofheatenergyisatworkintoday’sexperiment?

4. TrueorFalse:Waterispooratabsorbingheatenergy.a. Trueb. False


Lesson#8:Balloongymnastics

Overview:Heatcausesallkindsofthingstohappen.We’llzoominonthemicroscaleofmoleculesasweexploreintoday’slesson.

WhattoLearn:Heatenergyinfluencesallkindsofobservablephenomenaonourplanet.

Materials

water plasticbottle balloon stovetopandsaucepanorthesetupinthevideo

LabTime

1. Pouracoupleofinchesofwaterintoanemptysodabottleandcapwitha7‐9″balloon.Youcansecuretheballoontothebottlemouthwithastripoftapeifyouwant,butitusuallysealstightwithjusttheballoonitself.

2. Fillasaucepanwithaninchortwoofwater,andaddyourbottle.Heatthesaucepanoverthestovewithadulthelp,keepingacloseeyeonit.Turnofftheheatwhenyourballoonstartstoinflate.Sincewaterhasahighheatcapacity,thewaterwillheatbeforethebottlemelts.(Don’tbelieveme?TrytheFire‐WaterBalloonExperimentfirsttoseehowwaterconductsheatawayfromthebottle!)

3. Whenyou’refinished,stickthewholethinginthefreezerforanhour.Whathappenedtotheballoon?4. Recordallobservationsintheworksheet

BalloonGymnasticsObservations

1. Whathappenstotheballoonwhentheballoonisheated?Whatishappeningtoitsairmolecules?

2. Whathappenstotheballoonwhenyouputitinthefreezer?Whatishappeningwithitsmoleculesnow?


Reading

Thismaterialmaybehelpfultointerprettoday’sexperiment:

Isitwarmerupstairsordownstairs?Theupstairsinahouseiswarmerbecausethepocketsofwarmairrisebecausetheyarelessdensethancoolair.Themorethemoleculesmovearound,themoreroomtheyneed,andthefurthertheygetspacedout.Thinkofaswimmingpoolandapieceofaluminumfoil.Ifyouplaceasheetoffoilinthepool,itfloats.Ifyoutakethefoilandcrumpleitup,itsinks.Themorecompactlyyousquishthemoleculestogether,thedenseritbecomes.

Asforwhymountainsandvalleysareopposite,ithastodowiththeEarthbeingabigmassiveballofwarmrockwhichheatsuptheloweratmosphereinadditiontowindsblowingonmountainsandchangesinpressureasyougainaltitude…inanutshell,it’scomplicated!What’simportanttorememberisthattheEarthsystemisalotbiggerthanourbottle‐saucepanexperiment,andcan’tberepresentedinthisway.


1. Drawagroupofmoleculesataverycoldtemperatureinthespacebelow.Usecirclestorepresenteachmolecule.

2. TrueorFalse:Amoleculethatheatsupwillmovefaster.a. Trueb. False

3. TrueorFalse:Amaterialwillbelessdenseatlowertemperatures.a. Trueb. False


Lesson#9:Ghostcoin

Overview:Thisspookyideatakesalmostnotime,requiresadimeandabottle,andhasthepotentialforcreatingquiteastirinyournextmagicshow.Theideaisbasicallythis:whenyouplaceacoinonabottle,itstartsdancingaround.Butthere’smoretothistrickthanmeetsthescientist’seye.

WhattoLearn:Heatenergyiscarriedthroughdifferentsubstancesandaffectsthepropertiesofdifferenttypesofmatter

Materials Coin Freezer Plasticbottle(notglass)

LabTime

1. Removethecapofanemptyplasticwaterorsodabottleandreplaceitwithadime.2. Stickthewholethinguprightinthefreezerovernight.Makesureyourgroup’sbottleislabeled!First

thinginthemorning,takeitoutandsetitonthetable.Whathappens?3. Recordallobservationsintheworksheet.

GhostCoinObservations

Drawapictureofthewatermoleculesinsideofthewaterbottlewhenthisexperimentbegins.

Nowdrawapictureofwhattheylooklikeinthemorning.Whathappened?


Reading

Matterhasatendencytohangoutinfairlystablestatesundernormaltemperatures.Therearethreecommonstatesofmatter;solid,liquid,andgas.Thereisanotherstateofmattercalledplasma,butitisnotcommononEarth.Plasmaisahighlyenergizedgas.Itisusedinfluorescentlights.I’mgoingtoassumeyouknowabitaboutsolids,liquidsandgasessoIwon’tgointomuchdetailaboutthemhere(seeUnit3and8formoreinformation).

WhatIdowanttotalkaboutiswhathappensastemperatureschangeinasubstance.Let’stakeoneoftheneatestsubstancesontheEarth,water.Waterisquitespecialsinceitcanbeinitssolid,liquidandgasstateatrelatively“normal”temperatures.It’squitespecialforavarietyofotherreasons,too,butwe’llleaveitatthatfornow.

Pretendwehaveanicecubeonafryingpan(pooricecube).Rightnowthewaterisinasolidstate.It’sholdingitsshape.Themoleculesinthewaterareheldtogetherbystrong,stiffbonds.Thesebondsholdthewatermoleculesinatight,veryspecificpatterncalledamatrix.

Thismatrixholdsthewatermoleculesinacrystallinepatternandthesolidwaterholdsitsshape.Now,let’sturnontheheat.Theheatistransferredfromthestovetothefryingpantotheicecube.(We’lltalkaboutheattransferabitlater.)

Astheicecubeabsorbstheheat,themoleculesbegintovibratefaster(thetemperatureisincreasing).Whenthemoleculesvibrateatacertainspeed(gainenoughthermalenergy)theystretchthosestrong,stiffbondsenoughthatthebondsbecomemorelikerubberbandsorsprings.Whenthebondsloosenup,thewaterloosensupandbecomesliquid.Therearestillbondsbetweenthemolecules,buttheyareabitloose,allowingthemoleculestomoveandflowaroundeachother.

Theactofchangingfromasolidtoaliquidiscalledmelting.Thetemperatureatwhichasubstancechangesfromasolidtoaliquidiscalleditsmeltingpoint.Forwater,thatpointis32°For0°C.Nowwewillwatchcarefullyasouricecubecontinuestomelt(littleismoreexcitingthanwatchinganicecubemelt–golf,maybe).Abitafterweseeouricecubegofromsolidtocompletelyliquid,wenoticebubbling.What’sgoingonnow?Ifwewereabletoseethemoleculesofwateratthispointwe’dbequiteamazedatthefantasticscenebeforeus.

At212°For100°Cwatergoesfromaliquidstatetoagaseousstate.Thismeansthatthelooseygooseybondsthatconnectedthemoleculesbeforehavebeenstretchedasfarastheygo,can’tholdonanylongerand“POW!”theysnap.Thosewatermoleculesnolongerhaveanybondsandarefreetoroamaimlesslyaroundtheroom.Gasmoleculesmoveatveryquickspeedsastheybounce,jiggle,crashandziparoundanycontainertheyarein.Theactofchangingfromaliquidtoagasiscalledevaporationorboiling,andthetemperatureatwhichasubstancechangesfromaliquidtoagasiscalleditsboilingpoint.

Idon’tknowaboutyou,butIthinkit’sgettingabithotinhere.Let’sturntheheatdownabitandseewhathappens.Ifourgaseouswatermoleculesgetclosetosomethingcool,theywillcombineandturnfromgaseoustoliquidstate.Thisiswhathappenstoyourbathroommirrorduringashowerorbath.Thegaseouswatermoleculesthatarehavingfunbouncingandjigglingaroundthebathroomgetclosetothemirror.Themirroriscolderthantheair.Asthegasmoleculesgetclose,theyslowdownduetolossoftemperature.Iftheyslowenough,theyformlooseygooseybondswithothergasmoleculesandchangefromgastoliquidstate.

Theactofchangingfromgastoliquidiscalledcondensation.Thetemperatureatwhichmoleculeschangefromagastoaliquidiscalledthecondensationpoint.Cloudsaremadeofhundredsofbillionsoftinylittledropletsofliquidwaterthathavecondensedontoparticlesofsomesortofdust.Nowlet’sturntheheatdownabitmoreandseewhathappens.Asthetemperaturedropsandthemoleculescontinuetoslow,thebondsbetweenthemolecules


canpullthemtogethertighterandtighter.Eventuallythemoleculeswillfallintoamatrix,apattern,andsticktogetherquitetightly.Thiswouldbethesolidstate.Theactofchangingfromaliquidtoasolidiscalledfreezing,andthetemperatureatwhichitchangesiscalled(sayitwithmenow)freezingpoint.

Thinkaboutthisforasecond–isthefreezingpointandmeltingpointofanobjectatthesametemperature?Doessomethinggofromsolidtoliquidorfromliquidtosolidatthesametemperature?Ifyousaidyes,you’reright!Thefreezingpointofwaterandthemeltingpointofwaterareboth32°For0°C.Thetemperatureisthesame.Itjustdependsonwhetheritisgettinghotterorcolderastowhetherthewaterisfreezingormelting.Theboilingandcondensationpointisalsothesamepoint.NowI’mgoingtomessthingsupalittlebit.Substancescanchangestateattemperaturesotherthantheirdifferentfreezingorboilingpoints.Manyliquidschangefromliquidtogasandfromgastoliquidrelativelyeasilyatroomtemperatures.And,believeitornot,solidscanchangetoliquidsandevengasesandviceversaattemperaturesotherthantheusualmelting,freezing,orboilingpoints.Sowhat’sthepointofthepoints?

Atasubstance’sboiling,freezing,etc,points,allofthesubstancemustchangetothenextstate.Theconditionofthebondscannotremainthesameatthattemperature.Forexample,at100°Cwatermustchangefromaliquidtoagas.Thatisthespeedlimitofliquidwatermolecules.At100°Ctheliquidbondscannolongerholdonandallthemoleculesconverttogas.


1. Whenagasturnsintoaliquid,thisiscalled:a. Convectionb. Conductionc. Absorptiond. Condensation

2. Whenwaterboils,whathappenstothebondsbetweenitsmolecules?

3. Whatisthebestwaytodescribehowthebondsbetweenwatermoleculesbehavewheninaliquidstate?

a. Solidbridgesb. Rubberbandsc. Nobondsd. Brittlelikechalk

4. Thecrystallineshapeofasolidisreferredtoas:a. amatrixb. avortexc. acrystald. acube


Lesson#10:What’saJoule?

Overview:Energyshowsupinallkindsofways.We’llseehowtodaythroughasimplelesson.

WhattoLearn:Energyistheabilitytodowork.You’llgetpracticeplayingwithunitsandlearningabouthowwemeasureenergyandtheformsittake.

Materials

Somethingthatweighsaround100gramsor4ounces,aboutthesameasanapple Ameteroryardstick

LabTime

1. Grabyour100‐gramobject,putitonatable.2. Nowliftitoffthetablestraightupuntilyouliftitonemeter(oneyard).3. Liftitupanddown20times.4. Recordyourobservationsintheworksheet.

JouleObservations

1. Describetheenergyinyourobjectbeforeyoudoanythingtoit.Istheremorethanonewaytosaythis,intermsofunits?

2. Whenyoumovetheobjectoveronemeter,whatareyoudoing?3. Whenyoudothis20times,usemathtosayhowmanyJoulesofworkyouaredoing.4. HowmanyJoulesofworkdoyoudoifyoulifttheapple50times?

Reading

Ifwewishtotalkaboutenergyfurther,weneedtohaveaunitofmeasurement.Forenergy,acoupleofunitsaretheJouleandthecalorie.AJouleistheenergyneededtoliftoneNewtononemeter.ANewtonisaunitofforce.OneNewtonisabouttheamountofforceittakestolift100gramsor4ouncesoranapple.

Ittakesabout66Newtonstolifta15‐poundbowlingballanditwouldtakea250‐poundlinebackerabout1000Newtonstolifthimselfupthestairs!So,ifyouliftedanappleonemeter(about3feet)intotheairyouwouldhaveexertedoneJouleofenergytodoit.

Thecalorieisgenerallyusedtotalkaboutheatenergy,andyoumaybeabitmorefamiliarwithitduetofoodandexercise.AcalorieistheamountofenergyittakestoheatonegramofwateronedegreeCelsius.FourJoulesareaboutonecalorie.


A100‐gramobjecttakesaboutoneNewtonofforcetolift.SinceittookoneNewtonofforcetoliftthatobject,howmuchworkdidwedo?Rememberwork=forcexdistancesointhiscasework=1Newtonx20metersorwork=20Joules.

Youmayask,“Butdidn’twemoveit40meters,20metersupand20down?”That’strue,butworkismovingsomethingagainstaforce.Whenyoumovedtheobjectdownyouweremovingtheobjectwithaforce,theforceofgravity.Onlyinliftingitupareyouactuallymovingitagainstaforceanddoingwork.FourJoulesareabout1calorie,sowedid5caloriesofwork.

“Wow,Icanliftanapple20timesandburn5calories!Hellooooweightloss!”Well…notsofastthereRichardSimmons.Whenwetalkaboutcaloriesinnutritionwearereallytalkingaboutkilocalories.Inotherwords,everycalorieinthatpotatochipisreally1000caloriesinphysics.Soasfarasdietandexercisegoes,liftingthatappleactuallyonlyburned.005caloriesofenergy…rats.

Itisinterestingtothinkofcaloriesastheunitofenergyforhumansorasthefuelweuse.Theaveragehumanusesabout2000calories(foodcaloriesthatis,2,000,000actualcalories)adayofenergy.Running,jumping,sleeping,andeatingallusecalories/energy.Running15minutesuses225calories.Playingsoccerfor15minutesuses140calories.(Rememberthosearefoodcalories,multiplyby1000togetphysicscalories).Thiswebsitehasanicechartformoreinformation:Caloriesusedinexercise.

Everythingweeatrefuelsthatenergytank.Allfoodhascaloriesinitandourbodytakesthosecaloriesandconvertsthemtocalories/energyforustouse.Howdidthefoodgettheenergyinit?Fromthesun!Thesun’senergygivesenergytotheplants,andwhentheanimalseattheplantstheygettheenergyfromthesunaswell.

So,ifyoueatacarrotoraburgeryouaregettingenergyfromthesun!Eatingbroccoligivesyouabout50calories.Eatingahamburgergivesyouabout450calories!Weuseenergytodothingsandwegetenergyfromfood.Theproblemcomeswhenweeatmoreenergythanwecanuse.Whenwedothat,ourbodyconvertstheenergytofat,ourbody’sreservefueltank.Ifyouusemoreenergythenyou’vetakenin,thenyourbodyconvertsfattoenergy.That’swhyexerciseanddietcanhelpreduceyourweight.


1. Ifsomethinghasaweightof2Newtonsandismovedhalfameter,howmanyJoulesofenergyareused?Showyourwork.

2. Whatisthesourceofallthisenergywe’reworkingwithhere?

3. Itdoesn’tcountasworkwhenyoumovetheapplebackdown.Whynot?


Lesson#11:MeasuringPower

Overview:Todayyou’llmeasurepowerandhavesomehandytoolstobeabletorecordandinterpretdata.Weusethesamematerialsaslastlesson,butintroduceanimportantconcept:thatofpower.Powerisworkdoneovertimeandismeasuredinwatts,whichisaJoulepersecond.

WhattoLearn:You’llbeabletohavehands‐onexperienceandunderstandaworkingdefinitionofenergy,work,andpower.

Materials

Meteroryardstick Astopwatchortimer Object

LabTime

1. Grabyour100‐gramobjectandputitonatable.2. Nowliftitoffthetablestraightupuntilyouliftitonemeter(oneyard).3. Startthetimerandatthesametimestartliftingtheobjectupanddown20times.4. Stopthetimerwhenyou’redonewiththe20lifts.5. So,doyouhavethepoweroftheDodgeViper?Hmmm,probablynot,butlet’stakealook.6. Firstofall,figureouthowmuchworkyoudid.Work=forcexdistance,sotaketheforceyouusedand

multiplythatbythedistanceyoumovedit.Inthiscase,youcanmultiply1Newtonx20metersandget20Joulesofwork.

7. Nowfigureouthowmuchpoweryouused.Powerisworkdividedbytimesotakeyourwork(20Joules)anddivideitbyhowmuchtimeittookyoutodothatwork.Forexample,ifyouliftedtheblock20times(doing20Joulesofwork)in5seconds,youdid20Joules/5seconds=4Wattsofpower.ToconvertWattstohorsepowerwemultiplyby.001sointhisexample,youdid4x.001=.004horsepower.

8. Showyourcalculationsintheworksheetbelow.

MeasuringPowerCalculations

1. Howmuchworkdidyoudo?Showyourwork.(Nopunintended!)

2. Howmuchpowerdidyouuse?Showyourwork.



1. Whatiswork?a. Forcedividedbydistanceb. Forcetimesdistancec. Energyrequiredforpowerd. Kineticandpotentialenergy

2. Whatispower?a. Workdividedbytimeb. Workmultipliedbytimec. Energyusedinanexercised. Caloriesovertime

3. Howdowemeasurework?Nameoneunit.

4. Howdowemeasurepower?Nameoneunit.


Lesson#12:Steamboats

Overview:Thisexperimentprovidesacreativewaytoseehowsteamcanprovidepowerandofferusinsightintohowpowerisgeneratedthroughthiscommonmeans.

WhattoLearn:Manynaturalresourcescanmeetourenergyneeds.Weneedtoconverttheenergystoredinwaterintoenergythatwecanuseaselectricityorheat.

Materials

Coppertubing(1/8”‐1/4”diax12”long) Votivecandle Foamblock Scissorsorrazor(withadulthelp) Bathtub

LabTime

1. Wrapthecoppertubing2‐3timesaroundathickmarker.Youwanttocreatea”coil”withthetubing.Dothisslowlysoyoudon’tkinkthetubing.Endwithtwo3”paralleltails.(Thisiseasierifyoustartinthemiddleofthetubingandworkoutwardsinbothdirections.)

2. Stickeachtailthroughablockoffoam.Bendthewiressotheyrunalongthelengthofthebottomoftheboat,slightlypointedupwards.(Youcanalsouseaplasticbottlecutinhalf.)

3. Positionavotivecandleonthetopsideoftheboatandanglethecoilsoitsitsrightwheretheflamewillbe.4. Tostartyourboat,fillthebathtubwithwater.Whileyourtubfills,holdthetubingintherunningwaterand

completelyfillthecoilwithwater.5. Haveyouradulthelperlightthecandle.Inamoment,youshouldhearthe“puttputt”soundsoftheboat

working!6. Recordallobservationsintheworksheetbelow.

SteamboatObservations

1. Howisyourboatusingenergy?


2. Taketheweightofyourboatusingascale.Thenmeasurethedistanceittravels.Howmuchworkisyoursteamenginedoing?Showyourcalculationsbelow.

Yoursteamboatusesavotivecandleasaheatsourcetoheatthewaterinsidethecoppertubing(whichisyourboilingchamber).Whenthewaterisheatedtosteam,thesteampushesoutthetubeatthebackwithasmallburstofenergy,whichpushestheboatforward.

Sinceyourchamberissmall,youonlygetashort”puff”ofenergy.Afterthesteamzipsout,itcreatesalowpressurewhereitoncewasinsidethetube,andthisdrawsinfresh,coolwaterfromthetub.ThecandlethenheatsthisnewwateruntilsteamisproducedandPOP!itgoesouttheback,whichinturndrawsinmorecoolwatertobeheated…andonitgoes.The”clicking”or“puttputt”noiseyouhearisthesteamshootingouttheback.Thisgoesonuntilyoueitherrunoutofwaterorheat.

Troubleshooting:ifyourboatdoesn’twork,itcouldbeafewthings:

Thetubinghasanairbubble.Inthiscase,suckononeoftheendslikeastrawtodrawinmorewater.Heatinganairbubblewillnotmaketheboatmove–itneedstobecompletelyfilledwithwater.

Yourcoilisnothotenough.Youneedthewatertoturnintosteam,andinorderforthistohappen,youhavetoheatthecoilashotasyoucan.Movethecoilintoabetterpositiontogetheatfromtheflame.

Theexhaustpipesareangleddown.Youwantthesteamtomoveupandoutofyourpipes,notgetsuckedbackin.Adjusttheexittubingtailssotheypointslightlyupwards.

Reading

Solarcells,windturbines,andhydroelectricpowerplants(liketheHooverdam)areallexamplesofalternativeenergysources.Althoughlotsoffolksstillargueaboutwhat’sconsidered“alternative”ornot,thegeneralideaisthatthesourcesproducethesameenergyatlesscost,bothmoney‐wiseandenvironmentally.

Scientistsarenowworkingonsubstitutesfortraditionalmethodsofgeneratingpower.Forexample,theyhavefiguredoutwaystousealcoholinsteadoffossilfuels,coalinsteadofwood,andpetroleuminsteadofwhaleoil.

Sincealternativeenergyexperimentsinthisarearequirepowerplantsandmachinerythesizeofasmalltown,we’regoingtofocusonaveryspecializedformofalternativeenergycalledrenewableenergy.

Renewableenergyistheenergycreatedfromnaturalsources,likesunlight,water,wind,andtemperaturedifferences(geothermal).We’llmakesolar‐poweredrobots,buildsolarbatteries,lightupbulbsusingablastfromahairdryer,andcapturetheenergyinlightwavesonourbattery‐freeradio.

Steampowermayseemlikeanexampleoftraditionalenergyusage,wheninrealityitisabletosupplyasurprisingamountofrenewableenergyaswaterisheatedinasolarcollectiontower,geothermalplant,orbiomasspowerstation.



1. Namethreesourcesofrenewableoralternativeenergy:a.

b.

c.

2. Whyisitimportanttolookforrenewablesourcesofenergy?

3. Whatisoneexampleofafossilfuel?


Lesson#13:StirlingEngine

Overview:TheStirlingheatengineisverydifferentfromtheengineinyourcar.WhenRobertStirlinginventedthefirstStirlingenginein1816,hethoughtitwouldbemuchmoreefficientthanagasolineordieselengine.However,theseheatenginesareusedonlywherequietenginesarerequired,suchasinsubmarinesoringeneratorsforsailboats.You’regoingtomakeoneoutofsodacansandoldCDs.

WhattoLearn:AStirlingengineshowsushowenergyisconvertedandusedtodoworkforus.

Materials threesodacans oldinnertubefromabikewheel superglueandinstantdry electricalwire(3‐conductorsolidwire) 3oldCDs oneballoon penny nylonbushing(fromhardwarestore) smallcandleoralcoholburner fishingline(15lb.testorsimilar)

packofsteelwool drillwith1/16″bit pliers scissors razor wirecutters electricaltape pushpin permanentmarker Swissarmyknife(withcanopeneroption)

LabTime

1. Openeachsodacanandemptythesoda.Removethetopofonesodacanwithyourcanopener.Thisworkmosteasilybymovingalongtheridgeonthecan’slid.Becarefulnottocutyourself,souseadultsupervision.

2. Takethetopoffthesecondcaninthesameway,andthenremovethebottomofthesecondcancompletely,about¾inchabovethebottom.Useasharprazor.

3. Cuttheneckoffaballoontoserveasthepiston,andfititoverthelidofthecanopenatthetop.Usearubberbandtoattachitatthetopifneeded.Nowcutasquareoutoftheinnertubethatmeasures¾inchoneachside.Gluethetubesquareonthecenteroftheballoonandpushdownsoitstays.Todryitquickly,sprayinstantdryonit.

4. Takeapushpinandpokeaholeinthecenterofthetubesquare.Setthecanaside.5. Takeawaterbottlecapandmarkwherewewilldrillholes.Markonespotonthesideofthecap(about

halfwayup)andatanequalspotopposite.Alsomakeamarkinthecenterofthecap.Drilltheholeswithadulthelp,usingpliersandapieceofwoodtohelpmakepreciseholes.

6. Attachthebottlecaptotheoppositesideofthediaphragmonthesodacan(onthebottom),sotaketheballoonoff,andflipitupsidedown,stretchingitoverthelidagain.Thepointofthepushpinshouldpointup,sothreaditthroughtheholeinthemiddleofthecap.Secureitwithglue,anduseinstantdry.Setthisaside.

7. Grabtheothercanandprepareitfordrilling.Makeamarkabout1inchdownfromthetopofthecan,andmakeasimilarmarkontheexactoppositesideofthecan.Drilltheholes,usingapieceofwoodtohelpsupportthecanifneeded.Remembertouseadultsupervision!

8. Usethecirculartemplateandtapeitinplacetocutaviewinghole.Youwantthetemplatesecuredsothatitisnotonthesamesideastheholes.Markanoutlinewhereyouwillcut,andusearazortocutitout.


9. Bendthewireintheshapeofthecrankshaftaccordingtothetemplate.Useplierstohelp,cuttingthewiretoabout8inchestoensureaprecisefit.Benditwithyourfingerstomatchthetemplate.Maketwomarksaccordingtothetemplateandmakemarksonthewire.Atthispoint,youwillbendtheloopinthecrankshaft90degrees,usingtwopairsofpliersthistime.Makesuretheendsofthecrankshaftareasflatandstraightaspossible.Orientandplacethewireinsidethecanwiththeviewingholecutout.Checktomakesureitcanspinfreely.Securetheendswithpiecesoftapetostopitfromslidingout.

10. Tomakethedisplacer,takea16‐inchpieceofcopperwire,straighteningitasmuchaspossible.Useplierstocreateasmallhookofabout½inch.Usesteelwooltorollthewireup.Itshouldbethediameterofthesodacanoncerolledup.Checkthatitfitsintothebottomofthesodacanwithenoughclearancetofitinandoutfairlyeasily.Usetheplierstoworkthecopperwiretotheheightofthecan.

11. Takeyourfishinglineandcutoffafewinches,tyingitontotheloopofthewireinthedisplacer.Secureitwithsuperglueandinstantdryifnecessary.Threadthefishinglinethroughthediaphragm.Beforeyoudothis,takethediaphragmoffandputitbackonupsidedown,andpullthepushpinout,threadingthefishinglinethatthepushpinmade.Placesomeoilaroundthewiresothatitslidesmoreeasily.Testittoseethatthereisnodragwhenyouliftthewholedisplacer.

12. Nudgethedisplacerintothetopofthesodacanwiththetopcutoff.Putthediaphragmoverthetopofthecan,makingsurethebottlecapiscentered.Testagaintomakesurethedisplacerfallsfreely.Ifitdoesn’taddmoreoil.

13. Takeabout8inchesofcopperwireandstickitthroughtheholesinthesidesofthebottlecap.Bendeachsideofitwithpliers.Makesureitcanspinfreely,soleaveagaponeachsideofthecap.Usepliersagaintobendthesidesofthewiresintowardsthecenterofthecap,andthenagainsothatitcanfitinsidetheothercan.Bothsidesofthewireshouldtouchthecrankshaftinthecanabove.

14. Pressthetopcandownaroundthebottomcangently.Don’tcrushthecan;weonlywanttoeaseitdownabitfurthersothatitissecure.

15. Securethecranktothepushrodsbyorientingthelongparttowardsthebottomofthecan.Makeamarkabout½inchhigherthanthespotwhereitrestsonthecrank.Trimtherodsatthesemarkswithwirecutters.Allowtheconnectingrodstostickoutthefront,markthemabout¼inchfromtheend,andmakehooksatthesespots.Bendthehookswithplierssothattheystayonthecrank.Loopthehooksaroundthecranksothatwhenspun,thepushrodsallowthedisplacertomoveupanddown.Makesurethecrankturnsfreely.Ifyourballoonwantstopushtherodsupintothecranktoofar,simplybendthecornersinthepushrodsmoresharplytoshortentherods.Becarefulthatthefishinglinedoesn’tgetcaught.

16. Tiethefishinglinetothemiddleofthebiglooponthecrank.Makesuretheknotisn’tsotightthatitrestrictsthefreemovementofthecrankasitturns.Tapethetwostrandsoffishinglinetogether,andtrimthelooseendsofthelinewithscissors.

17. Tomaketheflywheel,grab3oldCDsorDVDs(anythingbyMichaelBaywillwork).Takeyourpieceofnylonbushing,whichshouldbeabout½indiameterand1inchlong.ItshouldfitthroughthecenteroftheCD.AttachtheCDstothebushing(makesureitfitsniceandsnug).

18. Sandtheendofthecrankshaftsothatitgluesmoreeasily.Hotgluethissidetothenylonbushing,generouslygluingthroughthecenterofthebushing.Checktoseethattheflywheelspinningwillcranktheengine.

19. Positionthecranksothatthelargecrankisfacingdownward.AttachapennytothetopsurfaceoftheCDtoserveasacounterweight.Thiswillallowtheenginetorunmoresmoothly.

20. Tomaketheengine’sbase,cutthetopandbottomoffacanaswedidbefore.Placeaburnerontheinsideatthebottom,andthentapeittothecan.Makeaholeforairwiththerazorinthesideofthecanatabouttheleveloftheflame.Cutafewmoreholesintheside.Theyshouldbebigenoughsothatyoucanlighttheburner.


21. Assembletheengineontopoftheburnerbase.Nowwe’rereadytotestthisthing,soremembertoputonsafetygoggles!Usealightertolighttheburner,andkeepahandonthetopofthecantokeepitsteady.Ifyouneedtogiveyourengineajumpstart,spintheflywheel.

22. Recordyourobservationsontheworksheet.

StirlingEngineObservations

1. Whathappenswhenyoustarttheengine?Whatisgoingon?

2. Grabacoldbottleofwaterandpourasmallamountintothetopofthebottlecap.Whathappens?Whydoesthishappen?

Thisenginewasdevelopedbecauseitwasquietandcouldusealmostanythingasaheatsource.Thiskindofheatenginesquishesandexpandsairtodomechanicalwork.There’saheatsource(thecandle)thataddsenergytoyoursystem,andtheresultisyourshaftspins(CD).

Thisengineconvertstheexpansionandcompressionofgasesintosomethingthatmoves(thepiston)androtates(thecrankshaft).Yourcarengineusesinternalcombustiontogeneratetheexpansionandcompressioncycles,whereasthisheatenginehasanexternalheatsource.


Reading

Here’showaStirlingengineisdifferentfromtheinternal‐combustionengineinsideyourcar.Forexample,thegasesinsideaStirlingengineneverleavetheenginebecauseit’sanexternalcombustionengine.Thisheatenginedoesnothaveexhaustvalvesastherearenoexplosionstakingplace,whichiswhyStirlingenginesarequieter.Theyuseheatsourcesthatareoutsidetheengine,whichopensupawiderangeofpossibilitiesfromcandlestosolarenergytogasolinetotheheatfromyourhand.

TherearelotsofdifferentstylesofStirlingengines.Inthisproject,we’lllearnabouttheStirlingcycleandseehowtobuildasimpleheatengineoutofsodacans.ThemainideabehindtheStirlingengineisthatacertainvolumeofgasremainsinsidetheengineandgetsheatedandcooled,causingthecrankshafttoturn.Thegasesneverleavethecontainer(remember–noexhaustvalves!),sothegasisconstantlychangingtemperatureandpressuretodousefulwork.Whenthepressureincreases,thetemperaturealsoincreases.Andwhenthetemperatureofthegasesdecreases,thepressurealsogoesdown.(Howpressureandtemperaturearelinkedtogetheriscalledthe“IdealGasLaw”.)

SomeStirlingengineshavetwopistonswhereoneisheatedbyanexternalheatsourcelikeacandleandtheotheriscooledbyexternalcoolinglikeice.Otherdisplacer‐typeStirlingengineshaveonepistonandadisplacer.Thedisplacercontrolswhenthegasisheatedandcooled.

ThisStirlingengineusestheheatfromacoffeecupandthecoolingfromtheambientair.

Inordertowork,theheatengineneedsatemperaturedifferencebetweenthetopandbottomofthecylinder.SomeStirlingenginesaresosensitivethatyoucansimplyusethetemperaturedifferencebetweentheairaroundyouandtheheatfromyourhand.OurStirlingengineusestemperaturedifferencebetweentheheatfromacandleandicewater.

Theballoonatthetopofthesodacanisactuallythe”powerpiston”andissealedtothecan.Itbulgesupasthegasexpands.Thedisplaceristhesteelwoolintheenginewhichcontrolsthetemperatureoftheairandallowsairtomovebetweentheheatedandcooledsectionsoftheengine.

Whenthedisplacerisnearthetopofthecylinder,mostofthegasinsidetheengineisheatedbytheheatsourceandgasexpands(thepressurebuildsinsidetheengine,forcingtheballoonpistonup).Whenthedisplacerisnearthebottomofthecylinder,mostofthegasinsidetheenginecoolsandcontracts.(Thepressuredecreasesandtheballoonpistonisallowedtocontract.)

Sincetheheatengineonlymakespowerduringthefirstpartofthecycle,there’sonlytwowaystoincreasethepoweroutput:Youcaneitherincreasethetemperatureofthegas(byusingahotterheatsource),orbycoolingthegasesfurtherbyremovingmoreheat(usingsomethingcolderthanice).

Sincetheheatsourceisoutsidethecylinder,there’sadelayfortheenginetorespondtoanincreaseordecreaseintheheatorcoolingsource.Ifyouuseonlywatertocoolyourheatengineandsuddenlypopanicecubeinthewater,you’llnoticethatittakesfivetofifteensecondstoincreasespeed.Thereasonisbecauseittakestimefortheadditionalheat(orremovalofheatbycooling)tomakeitthroughthecylinderwallsandintothegasinsidetheengine.SoStirlingenginescan’tchangethepoweroutputquickly.Thiswouldbeaproblemwhengettingonthefreeway!

Inrecentyears,scientistshavelookedtothisengineagainasapossibility,asgasandoilpricesrise,andexhaustandpollutantsareaconcernfortheenvironment.Sinceyoucanusenearlyanyheatsource,it’seasytopickonethathasalow‐fumeoutputtopowerthisengine.Scientistsandengineersareworkingonamodelthatusesa


Stirlingengineinconjunctionwithaninternal‐combustionengineinahybridvehicle…maybewe’llseetheseontheroadsomeday!


1. WhatistheprimaryinputofenergyfortheStirlingengine?

2. AsPressureincreasesinagas,whathappenstotemperature?a. Itincreasesb. Nothingc. Itdecreasesd. Itincreases,thendecreases

3. WhatistheprimaryoutputoftheStirlingengine?


Lesson#14:PeanutEnergy

Overview:Putyoursafetygogglesonfortoday’slab–we’llbelookingatfireagain.You’llbemeasuringhowmuchenergyapeanutholdsbysettingitonfireandmeasuringanincreaseinwatertemperature.

WhattoLearn:Allourenergyneedsonearthcomefromsomewhere.Wecannotmakeourownfood,butplantscan.Weareallconnectedtotheplantsandsoilsthattheygrowinbecausetheyprovideourverybasicneeds,aswellassomeofourmoremodernneeds.

Materials

Goggles 2shelledpeanuts Smallpairofpliers Matchorlighter Testtubeinwiretesttubeholders(theselooklikepliersthataredesignedtoholdatesttube) Scale Thermometer

LabTime

1. Todaywe’reworkingwithfire,sofollowallspecialinstructionsprovidedaboutworkingwithfiretoday.2. Measureyourtesttubeonthescalewhenit’sempty:_______________________grams3. Fillupyourtesttubewithabout10gramsofwaterandweighitagain:_______________________grams4. Measuretheinitialtemperatureofthewater:___________________________oC5. Putonsafetygoggles.6. Usingasmallpairofpliers,holdthepeanutandaskanadulttolightthepeanutwiththelighteruntilit

catchesfire.7. Uponignition(whenthepeanutisburningbyitselfanddoesn’tneedthelighter),holdthepeanutunderthe

waterclosetothebottomofthetesttubeuntilthepeanutstopsburning.8. Quicklymeasurethefinaltemperatureofthewater:___________________________oC9. Recordyourresultsontheworksheet.10. Allowthepeanuttocoolasyourecordyourobservationsandcompletethedatatables.


Let'stakeanexamplemeasurement.Supposeyoumeasuredatemperatureincreasefrom20°Cto100°Cfor10gramsofwater,andboiledoff2grams.Weneedtobreakthisproblemdownintotwoparts‐thefirstpartdealswiththetemperatureincrease,andtheseconddealswiththewaterescapingasvapor.

Thefirstbasicheatequationisthis:Q=mcT

Qistheheatflow(incalories)misthemassofthewater(ingrams)cisthespecificheatofwater(whichis1degreepercaloriepergram)andTisthetemperaturechange(indegrees)

Soourequationbecomes:Q=10*1*80=800calories.

Ifyoumeasuredthatweboiledoff2gramsofwater,yourequationwouldlooklikethisforheatenergy:Q=Lm

Listhelatentheatofvaporizationofwater(L=540caloriespergram)misthemassofthewater(ingrams)

Soourequationbecomes:Q=540*2=1080calories.

Thetotalenergyneededisthesumofthesetwo:

Q=800calories+1080calories=1880calories.

Reading

Didyouknowthateatingasinglepeanutwillpoweryourbrainfor30minutes?Theenergyinapeanutalsoproducesalargeamountofenergywhenburnedinaflame,whichcanbeusedtoboilwaterandmeasureenergy.

Peanutsarepartofthebeanfamily,andactuallygrowunderground(notfromtreeslikealmondsorwalnuts).Inadditiontoyourlunchtimesandwich,peanutsarealsousedinwoman'scosmetics,certainplastics,paintdyes,andalsowhenmakingnitroglycerin.

Whatmakesupapeanut?Insideyou'llfindalotoffats(mostofthemunsaturated)andantioxidants(asmuchasfoundinberries).AndmorethanhalfofallthepeanutsAmericanseatareproducedinAlabama.We'regoingtolearnhowtoreleasetheenergyinsideapeanutandhowtomeasureit.

There'schemicalenergystoredinsideapeanut,whichgetstransformedintoheatenergywhenyouigniteit.Thisheatflowstoraisethewatertemperature,whichyoucanmeasurewithathermometer.Youshouldfindthatyourpeanutcontains1500‐2100caloriesofenergy!Nowdon'tpanic‐thisisn'tthesameasthenumberofcaloriesyou'reallowedtoeatinaday.Theaveragepersonaimstoeataround2,000Calories(withacapital"C").1Calorie=1,000calories.Soeachpeanutcontains1.5‐2.1Caloriesofenergy(thekindyoueatinaday).Doyouseethedifference?

Sodidalltheenergyfromthepeanutgostraighttothewater,ordiditleaksomewhereelse,too?Theheatactuallywarmedupthenearbyair,too,butweweren'tabletomeasurethat.Ifyouwereafoodscientist,you'duseaniftylittledeviceknownasabombcalorimetertomeasurecaloriecontent.It'sbasicallyawell‐insulated,well‐sealeddevicethatcatchesnearlyalltheenergyandflowsittothewater,soyougetamuchmoreaccuratetemperaturereading.(Usingabombcalorimeter,you'dget6.1‐6.8Caloriesofenergyfromonepeanut!)


PeanutEnergyDataandObservations

Trial# MassofWater(grams)

TemperatureIncrease(oC)

HeatEnergy1(calories)

Sample

10grams 80oC=(10grams)x(1degreepercalpergram)x80(oC)

=800calories

Trial# MassofWaterBoiledOff(grams) HeatEnergy2(calories)

Sample

2grams=542caloriespergramx2grams

=1080calories


Trial# HeatEnergy1(calories) HeatEnergy2(calories) TotalEnergyProduced(calories)

Sample

800cal 1080cal 1880Calories


Part2EvaluationStudentWorksheet

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

LabTest&Homework

1. YourteacherwillcallyouupsoyoucansharehowmuchyouunderstandaboutEnergyandhowitworks.Sincescienceissomuchmorethanjustreadingabookorcirclingtherightanswer,thisisanimportantpartofthetesttofindoutwhatyoureallyunderstand.

2. Whileyouarewaitingforyourturntoshowyourteacherhowmuchofthisstuffyoualreadyknow,yougettogetstartedonyourhomeworkassignment.Theassignmentisduenextweek,andhalfthecreditisforcreativityandtheotherhalfisforcontent,soreallyletyourimaginationflyasyouworkthroughit.Chooseone:a. Writeashortstoryorskitaboutenergy,power,orworkfromtheperspectiveoftheobject(likeaball

orpendulumorrollercoaster).You’llreadthisaloudtoyourclass.b. Makeaposterthatteachesthemainconceptsofkineticandpotentialenergy.Whenyou’refinished,

you’lluseittoteachtoaclassintheyoungergradesanddemonstrateeachoftheprinciplesthatyou’velearned.

c. Writeandperformapoemorsongaboutwork,power,and/orenergy.Thiswillbeperformedforyourclass.


Part2Quiz

Name__________________________________________________________

1. Whattypeofheatenergyistransmittedbythesun?a. Conductionb. Convectionc. Plasmad. Radiation

2. Circlethefollowingphenomenainfluencedbythesun:a. Pressureb. Climatec. Weatherd. Wind

3. Whenyoureadamps,youread:a. Currentb. Voltagec. PowerDrawd. Work

4. Namethreesourcesofrenewableenergy:a. b. c.

5. Whatunitsdoweusetomeasureenergy?a. Kilowattsb. Joulesc. Newtonsd. Kilowatt‐hours

6. TrueorFalse:Waterispooratabsorbingheatenergy.a. Trueb. False

7. TrueorFalse:Amoleculethatheatsupwillmovefaster.a. Trueb. False

8. TrueorFalse:Amaterialwillbelessdenseatlowertemperatures.a. Trueb. False

9. Ifsomethinghasaweightof2Newtonsandismovedhalfameter,howmanyJoulesofenergyareused?Showyourwork.


10. Whatiswork?a. Forcedividedbydistanceb. Forcetimesdistancec. Energyrequiredforpowerd. Kineticandpotentialenergy

11. Whatispower?a. Workdividedbytimeb. Workmultipliedbytimec. Energyusedinanexercised. Caloriesovertime

12. Whyisitimportanttolookforrenewablesourcesofenergy?


Part2LabPracticalStudentWorksheet

Thisisyourchancetoshowhowmuchyouhavepickeduponimportantkeyconcepts,andifthereareanyholes.Youalsowillbeworkingonahomeworkassignmentasyoudothistestindividuallywithateacher.

Materials:

Somethingthatweighs100grams(likeanapple) Ameterstick Acalculator Scale

LabPractical:

Youwilldemonstratethatyouknowhowenergyismeasuredandhowworkisdoneusingthematerials.

1. Inyourownwordsdescribewhatworkis.

2. Measuretheweightoftheobjectingrams.Recordyourmeasurementhere:

3. Movetheobjectonemeter5times.Howmuchworkdidyoudo?Recordyourdatahere:


AnswerstoExercises

Lesson1:Cansolarenergybeconcentrated?

1. Namethreeusesforsolarenergy:(electricity,airconditioning/climatecontrol,watertreatment,solarfurnace,oven

2. Whattypeofheatenergyistransmittedbythesun?(radiation)3. Circleallthefollowingphenomenainfluencedbythesun:(wind,climate,weather)

Lesson2:SolarBattery

1. Thesunlightcausestheelectronstoflowfromthecuprousoxidebecauseofthe:(photoelectriceffect)2. Whatmaterialdomostsolarcellsuseinsteadofcopper?(silicon)3. Whatpartoftheelectromagneticspectrumismostactiveinthisexperiment?(UVlight)4. Whenyoureadamps,youread:(current)

Lesson3:SolarDrinkingBird

1. Wheredoesmostoftheenergyonearthcomefrom?(thesun)2. Whatisonewaythatweuseenergyfromthesun?(plants,solarpower)3. Whatistheprocessbywhichtheliquidisbeingheatedinsidethebird?(evaporation)

Lesson4:Canwindbeusedasasourceofenergy?

1. Namethreesourcesofrenewableenergy:(solar,hydropower,biomass,wind,geothermal)2. Whatdoesthesunhavetodowithwind?(createsareasofhigherandlowerpressureairbyheatingthem,

whichmakestheairmoveaswind)3. Namethreeexamplesofwindpowerinhistoricalorcurrentusage:(windmills,sailing,electricity)

Lesson5:WindTurbine

1. Trueorfalse:Electricityinawindturbineiscreatedbymagnetsintheturbine:(true)2. Whatisoneadvantageofusingwindforelectricity?(nopollution,lessrelianceonfossilfuels)3. Whatmightbeoneproblemwithconstructingwindfarmstomeetallourenergyneeds?(mightkillbirds)

Lesson6:Canwaterbeusedtostoreenergy?

1. Whattypeofheattransferisatworkinasolarpond?(convection)2. Whatunitsdoweusetomeasureenergy?(Joules)


3. Drawadiagramofasolarpondinthespacebelow:(shouldshowsaltwateronbottom,layeroffreshwater,andheatstoredintheupperlayerbythesun’sraysfromabove)

Lesson7:FireWaterBalloon

1. Whatisspecificheat?(theamountofheatenergythatmaterialmustabsorbtoincreaseintemperature1degreeC)

2. Nametwotypesofheatenergy(conduction,convection,andradiation)3. Whattype(ortypes)ofheatenergyisatworkintoday’sexperiment?(radiationandconvection)4. TrueorFalse:Waterispooratabsorbingheatenergy.(false)

Lesson8:BalloonGymnastics

1. Drawagroupofmoleculesataverycoldtemperatureinthespacebelow.Usecirclestorepresenteachmolecule.(shouldbegroupedverytightly)

2. TrueorFalse:Amoleculethatheatsupwillmovefaster(true)3. TrueorFalse:Amaterialwillbelessdenseatlowertemperatures(false)

Lesson9:GhostCoin

1. Whenagasturnsintoaliquid,thisiscalled:(condensation)2. Whenwaterboils,whathappenstothebondsbetweenitsmolecules?(Theysnaporbreak.)3. Whatisthebestwaytodescribehowthebondsbetweenwatermoleculesbehavewheninaliquidstate?

(rubberbandsorelastic)4. Thecrystallineshapeofasolidisreferredtoas:(amatrix)

Lesson10:What’saJoule?

1. Ifsomethinghasaweightof2Newtonsandismovedhalfameter,howmanyJoulesofenergyareexpended?(1Joule)

2. Whatisthesourceofallthisenergywe’reworkingwithhere?(thesun)3. Itdoesn’tcountasworkwhenyoumovetheapplebackdown.Whynot?(Theforceofgravitydoesthe

work,notyourarm.)

Lesson11:MeasuringPower

1. Whatiswork?(forcetimesdistance)2. Whatispower?(workovertime)3. Howdowemeasurework?Nameoneunit.(Joule,calorie)4. Howdowemeasurepower?Nameoneunit.(Watt,horsepower)


Lesson12:Steamboats

1. Namethreesourcesofrenewableoralternativeenergy:(wind,solar,water,geothermal,wave,tide,biomass)

2. Whyisitimportanttolookforrenewablesourcesofenergy?(Becauseothersourceslikefossilfuelsarefiniteandwillrunout.)

3. Whatisoneexampleofafossilfuel?(coal,oil,naturalgas)

Lesson13:StirlingEngine

1. WhatistheprimaryinputofenergyfortheStirlingengine?(thecandle)2. AsPressureincreasesinagas,whathappenstotemperature?(Itincreases.)3. WhatistheprimaryoutputoftheStirlingengine?(themovingpiston)


VocabularyfortheUnit

Alternativeenergyisenergyobtainedfromnon‐fossilfuelsources.Thisisalsoknownasrenewableenergy.

Conductionisheatenergytransferreddirectlybetweensubstances.

Convectionisheatenergyexchangedthroughintermediarymolecules.

Energyistheabilitytodowork.

Jouleisthestandardunitusedtomeasureenergy,definedasoneNewtonofforcemovedover1meter.

Kineticenergyistheenergyofmotionthatanobjecthaswhenitispushed,flies,orfalls.

Potentialenergyistheenergythatanobjecthasinrelationtothesysteminwhichitexists.

Powerisworkdoneoveraperiodoftime.

Specificheatishowmuchheatenergyamassofamaterialmustabsorbbeforeitincreases1°C.

Radiationisenergytransmittedthroughtheelectromagneticspectrum,onourplanetfromthesun.

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