2021 FJS 4E Phy Prelim P2

FAJARSECONDARYSCHOOL2021PRELIMINARYEXAMINATIONSSECONDARY4EXPRESS CANDIDATENAME CLASS INDEXNUMBERN/OLEVELINDEXNUMBER PHYSICSPaper2 NoAdditionalMaterialsRequired 6091/02 Date: 1September2021Duration:1hour45minutes READTHESEINSTRUCTIONSFIRST Writeyourname,classandindexnumberonalltheworkyouhandin.Writeindarkblueorblackpen.Youmayusepencilforanydiagrams,graphs,tablesorroughworking.Donotusestaples,paperclips,highlighters,glueorcorrectionfluid. SectionAAnswer allquestionsinthespacesprovided SectionBAnswerall threequestions,thelastquestionisintheformeither/or.Answer allquestionsinthespacesprovided. Attheendoftheexamination,fastenallyourworksecurelytogether.Thenumberofmarksisgiveninbrackets[]attheendofeachquestionorpartquestion.Incalculations,youshouldshowallstepsinyourworking,givingyouranswerateachstage.Theuseofanapprovedscientificcalculatorisexpected,whereappropriate. ForExaminer’sUse Paper1 40Paper2SectionA 50Paper2SectionB 30 Donot openthisdocument till permissionisgiven. Thisdocumentconsistsof 20printedpagesand0blankpages.

2 Total 120 SectionA[50marks] Answer allquestionsinthespacesprovided. ForExaminer’sUse 1 Fig.1.1showsahorizontalforceFpullingacarttowardstheright.Apendulumbobishangingfromaretortstandonthecart. Asthecartmoves,thependulumremainstiltedatanangleof20°tothevertical.Theweightofthebobis7.0N. Fig. 1.1 Drawascaleddiagramtodeterminethenetforceactingonthependulumbobwhenthecartismovinghorizontallytowardstheright.

3 netforce=………………………… [3] [Total:3]2 Amanpushesaboxofmass40kgalongastraighthorizontalpath. Fig.2.1showshowtheforceexertedbythemanvarieswiththedistancemovedbythebox. ForExaminer’sUse Fig. 2.1 (a) Theboxstartsfromrestandreachesavelocityof1.5m/safterittravelsadistanceof6.0m. (i) Calculatethegaininkineticenergyofthebox. kineticenergygained=………………………… [1] (ii) Calculatetheresistiveforceexperiencedbytheboxasittravelsadistanceof6.0m. resistiveforce=………………………… [3] (b) Themanpushestheboxforatotaldurationof10s.Calculatetheaveragepowerexertedbytheman. [TurnOver

4 averagepower=………………………… [2] [Total:6] 3 Fig.3.1showstheinteriorofaspraycan.Itisfirstfilledwithaliquidandtheninjectedwithgas.Thespraycaptrapsthehighlycompressedgaswithinthecan.Whenused,someoftheliquidleavesitandthepressuredecreases. ForExaminer’sUse Fig. 3.1 (a) Explain,usingmotionofmolecules,howthegasexertsapressureonthespraycan. ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… [2] (b) Afterusingmuchoftheliquid,therateatwhichtheliquidissprayedoutdecreases. (i) Usingideasaboutmolecules,explainwhythishappens. ……………………………………………………………………………………..… …………………………………………………………………………………..…… ………………………………………………………………………………..……… ………………………………………………………………………………..……… [2] (ii) Explainwhythetemperatureinsidethespraycandecreases. ……………………….………………………………………………………………

5 …………………….………………………………………………………………… [1] [Total:5] 4 Fig.4.1showsawomanofmass60kgpushingherselfupfromtheground.Thegravitationalfieldstrengthis10N/kg. ForExaminer’sUse Fig. 4.1 (a) OnFig.4.1,markandlabelthefollowingthreeforces.● weightofthewoman, W● forceF,bythegroundonbothhands● forceN,bythegroundonbothknees. Showclearlywhereeachforceactsandthedirectionofeachforce. [3] (b) Statetheprincipleof moments. ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… [1] (c) DeterminethemagnitudeofforceFwhenthewomanpushesherselfupfromthegroundtothepositionshowninFig.4.1 [TurnOver

6 F=………………………… [3] (d) CalculatetheforceNactingonbothknees. N=………………………… [1] [Total:8] 5 (a) Comparethearrangementandmotionoftheparticlesiniceandinliquidwater. ForExaminer’sUse arrangement………………………………………………………………………………… ………………………………………………………………………………………………… motion……..………………………………………………………………………………… ………………………………………………………………………………………………… [2] (b) Alakehasalayeroficeonitssurface.Theareaofthelakeis1800m 2 .Theicehasathicknessof0.025m.Thedensityoficeis920kg/m 3 . (i) Calculatethemassoficeonthelake. mass=………………………… [2] (ii) Atnight,thetemperatureoftheiceonthelakefallsby3.5°C.Thespecificheatcapacityoficeis2.1×10J/kg°C.Calculatethechangeinenergyasthetemperaturefalls. energy=………………………… [2] [Total:6]

7 6 Duringtheopeningofthe1996OlympicGamesinAtlanta,USAwastelevisedlivearoundtheworld,includingSingapore.Thetelevisionsignalwascarriedbyelectromagneticwavesviaasatellitepositioned35700kmabovethesurfaceofEarthasshownonFig.6.1. ForExaminer’sUse Fig. 6.1 (a) NametheelectromagneticwaveusedinthesignaltransmissionfromAtlantatoSingaporeandstateanotherapplicationofthiselectromagneticwave. electromagneticwave…………………………….………………………………………… application…………………………………………………………………………………… [2] (b) Thefrequencyofthesignalusedwas12GHz. (i) Determinetheperiodofthetelevisionsignal. [TurnOver

8 period=………………………… [2] (ii) Calculatethewavelengthoftheelectromagneticwaveusedinthetransmission. wavelength=………………………… [2] (c) Duetooccasionallossintransmission,anupsetviewerfromSingaporeproposedtwoalternativestothetypeoftransmissionusedbythesatellite–laserlightandultrasound. (i) Identifyonedifferencebetweenlaserlightandultrasound. ……………………….……………………………………………………………… …………………….………………………………………………………………… [1] (ii) Suggestareasonwhyusingultrasoundinsatellitetransmissionsisnotagoodidea. ForExaminer’sUse ……………………….……………………………………………………………… …………………….………………………………………………………………… [1] [Total:8] 7 Fig.7.1isacircuitdiagram. Fig. 7.1 (a) StatethenamesofcircuitcomponentsA, BandC. A…………………………………………………….. B…………………………………………………….. C…………………………………………………….. [2] (b) Thecircuitcanbeusedtoindicateachangeintemperature.

9 Stateandexplainwhatwouldbeobservedwhenthetemperaturechangesfromhottocold. ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… [4] [Total:6] 8 Fig.8.1showsanelectricalwiringinawaterheater. Itconsistsofaheatcoilrated'240V,2500W'andanexhaustfanrated'240V,300W'.Themainssupply240Vtothewaterheater. Fig8.1 ForExaminer’sUse (a) Explainhowafuseprotectsthecircuit. ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… [2] (b) ThefuseratinginFig8.1is11.0A.Explain,usingsuitablecalculations,whythefuseisnotsuitable. [TurnOver

10 ………………………………………………………………………………………………… ………………………………………………………………………………………………… [2] (c) IdentifytwootherfaultsinFig8.1anddescribehowtheyshouldbecorrected. 1……………………………………………………………………………………………… ………………………………………………………………………………………………… 2……………………………………………………………………………………………… ………………………………………………………………………………………………… [2] (d) Calculatethetotalresistanceofthecircuitwhenbothappliancesareinuse. ForExaminer’sUse totalresistance=………………………… [2] [Total:8]