4E Phy Prelim 2021 P2

BOONLAYSECONDARYSCHOOL PRELIMINARYEXAMINATION 2021 Name ( ) Class Subject : PHYSICSPaperNo : 2SubjectCode : 6091/02Level : SECONDARYFOUREXPRESSDate/Day : 16SEPTEMBER/THURSDAYTime : 0815–1000Duration : 1HOUR45MINUTES READTHESEINSTRUCTIONSFIRST Donot openuntil youaretoldtodoso. Beforeyoustart your exam, checkthat youhavereceivedthecorrect paperandthenumberofprintedpagesarecorrect.Writeyournameandindexnumberonalltheworkyouhandin.Donotusestaples,paperclips,glueorcorrectionfluid. Theuseofanapprovedscientificcalculatorisexpected,whereappropriate.Youmaylosemarksifyoudonotshowyourworkingsorifyoudonotuseappropriateunits. INFORMATIONTOCANDIDATES SectionAAnswer allquestions.Writeyouranswersinthespacesprovided. SectionBAnswer allquestions.Writeyouranswersinthespacesprovided.Question12hasachoiceofpartstoanswer. Attheendofexamination,fastenallyourworksecurelytogether.Thenumberofmarksisgiveninbrackets[ ]attheendofeachquestionorpartquestion.

2 Thisquestionpaperconsistsof19printedpages. SectionA[50marks]Answer allthequestions. ForExaminer’sUse 1 Fig.1.1showsabungeeridewhichlaunchespeopleupwardsusingelasticcords.Eachcordappliesaforceof1000Nandthecordsareat60 o fromeachother. Drawasuitablescalediagramtodeterminethemagnitudeanddirectionof theresultantofthesetwoforces. BLS/Prelim/2021/4E/Physics/6091/02

3 scale=……………………………..resultantforce=…………………………….directionofresultantforce=……………………………. [5]2 AuniformrodABof length3.0mweighs10N.Itissuspendedbytwoidenticalstringsat pointsXandYasshowninFig. 2.1. T1 and T2 arethetensioninthestrings. ForExaminer’sUse Fig. 2.1 Twoweights,20Nand40N,arehungfromtherodatpointAand1.6mfromXrespectively. (a) DrawtheweightoftherodinFig.2.1andlabelitW.IndicateclearlyitsdistancefrompointA. [1] (b) DetermineT2 ,thetensionofthestringatY. T2 =……………………………. [2] (c) Hence,orotherwise,determineT1 ,thetensionofthestringatX. T1 =……………………………. [2] BLS/Prelim/2021/4E/Physics/6091/02

4 3 Astudentmeasuresthepressureinsideabicycletyreusingapressuregaugehehasconstructed.Fig.3.1showstheapparatusheuses.Thepistonandrodmovealongthesmoothcylindricaltube. Thechangeinlengthofthespringisproportionaltotheforceappliedtothespring.Aforceof2.8Ncompressesthespringby2.0cm. Thestudentconnectsthepressuregaugetothetyre.Airfromthetyreexertsaforceonthepiston.Asthepistonmoves,thespringiscompressed.Thepistonmoves10cmtotherightandthenstops. ForExaminer’sUse (a) Calculatetheforceexertedonthepistonbythespring. forceexerted=……………………………. [1] (b) Thecross-sectionalareaofthepistonis3.0×10 –5 m 2 .Calculatethepressureoftheairinsidethetyre. pressure=……………………………. [2] (c) Suggestonechangetotheapparatussothatthepistonisabletomeasureawiderrangeofpressurewithoutchangingthelengthoftheapparatus. ………………………………………………………………………………………….. [1] (d) Eachtimethat thepressuregaugeisused, thepressureinthetyrefallsslightly.Thevolumeofthetyreandtemperaturestayconstant.Describe,usingideasaboutmolecules,whythepressurefalls. …………………………………………………………………………………………..…………………………………………………………………………………………..…………………………………………………