AQA GCSE Physics -Paper 2
Scalaroo-ooCORRECTooANSWERS-
quantitiesoowithooonlyoomagnitudeoosuchooasoospeed,oodistance,ootimeooandoomass.
Vectoroo-ooCORRECTooANSWERS-
quantitiesoowithooaoomagnitudeooandoodirectionooe.g.ooacceleration,ooforceoomomentumoo
andooweight.ooAoovectorooquantityoocanoobeoorepresentedooasooanooarrow,ootheoosizeoorep
resentingootheoomagnitudeooandootheoodirection,ootheoodirection.
Non-contactooforceoo-ooCORRECTooANSWERS-
theooobjectsooareoophysicallyooseparateooe.g.oomagnetism/gravity/electrostatic.
3oonon-contactooforcesoo-ooCORRECTooANSWERS-magnetismoo
gravity
electrostatic
Contactooforceoo-ooCORRECTooANSWERS-objectsooareoophysicallyootouchingoo.
3oocontactooforcesoo-ooCORRECTooANSWERS-friction
resistance
tension
Gravityoo-ooCORRECTooANSWERS-
Weightooisootheooforceooactingooonooanooobjectoodueootooogravity,ooitooactsooonooanooobjec
tsoo'centreooofoomass'ooandooisoodirectlyooproportionalootooomass
WeighooEquationoo-ooCORRECTooANSWERS-
Weightoo=oomassooxoograv.oofieldoostrength
Resultantooforcesoo-ooCORRECTooANSWERS-
Aoonumberooofooforcesooactingooonooanooobjectoomayoobeooreplacedoobyooaoosingleooforce
oothatoohasootheoosameooeffectooasooallootheoooriginalooforcesooactingootogether,oothisoosin
gleooforceooisootheoocalledootheooresultantooforce.
Inooaootugooofoowar,oo1000Nootoootheooleftooandoo800Nootoootheooright.ooTheooresultantoofo
rceooisoo200Nootoootheooleft
,Free-Bodyooforceoodiagramsoo-ooCORRECTooANSWERS-
Whenooanooobjectooisooactedooonoobyoomoreoothanoooneooforceooyouoocanoodrawooaoofree-
bodyooforceoodiagramootoooworkoooutootheooresultantooforceooonootheooobject.ooItooshowso
otheooforcesooactingooonooanooobjectoowithoutooanyoootherooobjectsoooroootherooforcesoosh
own.ooEachooforceooisooshownooonootheoodiagramoobyooaoovector,oowhichooisooanooarrowoo
pointingooinootheoodirectionooofootheooforce.oo(ootheoonormalooforceooisoothatoocomponentoo
ofootheoocontactooforceoothatooisooperpendicularootoootheoosurfaceoothatooanooobjectoocont
acts)
Howootoooresolveooforcesoo(forceoodiagramoosteps)oo-ooCORRECTooANSWERS-
1.ooDecideooonooaooscaleooofooNooperoocm.
2.ooDrawootheoo2oogivenooforces,oogivingoorespectootoootheiroolengthoo(moreoocmooifoomor
eooN)ooandootheooangleoothatooyouooareoogiven
3.ooDrawooaoolineooconnectingootheooendooofootheoo2oootheroolinesootoooformooaootriangle
4.ooMeasureootheoolengthooofoothisooline,oothenooconvertooitootoooNoobyoousingootheooscale
RelationshipoobetweenooJoulesooandooworkoodoneoo-ooCORRECTooANSWERS-
Whenooaooforceoocausesooandooobjectootooomove,ooworkooisoodoneooonootheooobjectoosooo
whenootheooforceoocausesoodisplacement.ooOneoojouleooofooworkooisoodoneoowhenooaoofor
ceooofoo1oonewtonoodisplacesooanooobjectoo1oometre.oo1ooJouleoo=oo1oonewton-metre.
Equationooforoowordoodoneoo-ooCORRECTooANSWERS-
workoodoneoo=ooforceooxoodistance
ElasticooDeformationoo-ooCORRECTooANSWERS-
Whenooanooelasticooobjectooisoostretched,oobent,ootwistedoooroocompressedooitoowillooretur
nootoooitsoooriginalooform
InelasticooDeformationoo-ooCORRECTooANSWERS-
Polyetheneoobagsoowilloonotooreturnootoootheiroooriginalooshapeooafteroobeingoodeformed,o
othisooisooinelastic.
Hooke'sooLawoo-ooCORRECTooANSWERS-
Theooextensionooofooanooelasticooobjectooisoodirectlyooproportionalootoootheooforceooapplie
dooasoolongooasootheoolimitooofooproportionalityooisoonotooexceeded:
Equationooforooforceoo(Hooke'soolaw)oo-ooCORRECTooANSWERS-
forceoo=oospringooconstantooxooextention
Extensionooandoocompression'soorelationshipoowithooelasticoopotentialooenergyooexplanati
onoo-ooCORRECTooANSWERS-
Aooforceoothatoostretchesoooroocompressesooaoospringoodoesooworkooandooelasticoopotenti
alooenergyooisoostoredooinootheoospring,ooprovidedootheoospringooisoonotooelasticallyoodefor
, med,ootheooworkoodoneooandooelasticoopotentialooenergyooareooequal.ooBeforeootheoolimito
oofooproportionalityooisoobreechedootheoorelationshipooisoolinearoo(directlyooproportional)oo
afterwardsooitooisoonon-linear
Elasticoopotentialooenergyooequationoo(given)oo-ooCORRECTooANSWERS-
Elasticoopotentialooenergyoo=oo1/2ooxoospringooconstantooxooextension^2
Momentoomeaningoo-ooCORRECTooANSWERS-
Theooturningooeffectooofooaooforceooisoocalledooitsoo'moment'
Momentooequationoo-ooCORRECTooANSWERS-momentoo=ooforceooxoodistance
Balancingoo-ooCORRECTooANSWERS-
Ifooanooobjectooisoobalancedootheooclockwiseoomomentooisooequalootoootheooanticlockwiseo
omoment.
Leversoo-ooCORRECTooANSWERS-
Aooleverooconsistsooofooaooload,ooeffortooandoopivot,ooleversoouseoomomentsootooomultiplyo
oaooforce,ootheyooallowooaoolargerooforceootoooactooonootheooloadoothatooisoosuppliedoobyoot
heooeffort.
EngineooGearsoo-ooCORRECTooANSWERS-
Engineoogearsoohaveootwooomainoojobs,ooproducingootorqueooandoospeed,oohoweveroothe
yooareooinverselyooproportionaloosooogearsooareoomadeootooomakeooaoocompromiseoobetw
eenootheootwoooinooanyoogivenoosituation.
Whenoostartingooaoocarooweoowantoohighootorque,oowhichoomeansoobeingooableootooocarry
ooaoogreaterooloadoo,ooandooconsequentiallyoolessoospeed.ooInoolowoogearsoothisooisooachi
evedooas...oo-ooCORRECTooANSWERS-
1.ooTheooengineoocausesooaoosmalloocogooonootheooengineooaxleootooorotate.
2.ooTheoosmalloocogooonootheooengineooaxleooisooconnectedootoooaoolargeroocogooonootheo
owheelooaxle,oowhichooincreasesootheootorqueoo(moment)ooexerted.
3.Aoohighooturningooforceoobutoolowoospeedooisooexertedooonootheoowheeloo(lowoogear)
Whenooaoocarooisooalreadyoomoving,ooweoowantooaoohighoospeedoowhichooisooachievedooa
s...oo-ooCORRECTooANSWERS-
1.Theooengineoocausesooaoolargeroocogooonootheooengineooaxleootoooturn.
2.Theoolargeroocogooonootheooengineooaxleooisooconnectedootoooaoosmalleroocogooonootheo
owheelooaxle,oocausingooaoohighoorateooofoorotation,oobutooaoolowooturningooforce.
3.ooTheoowheeloorotatesooquickly,oocausingooaoohighoospeed
Scalaroo-ooCORRECTooANSWERS-
quantitiesoowithooonlyoomagnitudeoosuchooasoospeed,oodistance,ootimeooandoomass.
Vectoroo-ooCORRECTooANSWERS-
quantitiesoowithooaoomagnitudeooandoodirectionooe.g.ooacceleration,ooforceoomomentumoo
andooweight.ooAoovectorooquantityoocanoobeoorepresentedooasooanooarrow,ootheoosizeoorep
resentingootheoomagnitudeooandootheoodirection,ootheoodirection.
Non-contactooforceoo-ooCORRECTooANSWERS-
theooobjectsooareoophysicallyooseparateooe.g.oomagnetism/gravity/electrostatic.
3oonon-contactooforcesoo-ooCORRECTooANSWERS-magnetismoo
gravity
electrostatic
Contactooforceoo-ooCORRECTooANSWERS-objectsooareoophysicallyootouchingoo.
3oocontactooforcesoo-ooCORRECTooANSWERS-friction
resistance
tension
Gravityoo-ooCORRECTooANSWERS-
Weightooisootheooforceooactingooonooanooobjectoodueootooogravity,ooitooactsooonooanooobjec
tsoo'centreooofoomass'ooandooisoodirectlyooproportionalootooomass
WeighooEquationoo-ooCORRECTooANSWERS-
Weightoo=oomassooxoograv.oofieldoostrength
Resultantooforcesoo-ooCORRECTooANSWERS-
Aoonumberooofooforcesooactingooonooanooobjectoomayoobeooreplacedoobyooaoosingleooforce
oothatoohasootheoosameooeffectooasooallootheoooriginalooforcesooactingootogether,oothisoosin
gleooforceooisootheoocalledootheooresultantooforce.
Inooaootugooofoowar,oo1000Nootoootheooleftooandoo800Nootoootheooright.ooTheooresultantoofo
rceooisoo200Nootoootheooleft
,Free-Bodyooforceoodiagramsoo-ooCORRECTooANSWERS-
Whenooanooobjectooisooactedooonoobyoomoreoothanoooneooforceooyouoocanoodrawooaoofree-
bodyooforceoodiagramootoooworkoooutootheooresultantooforceooonootheooobject.ooItooshowso
otheooforcesooactingooonooanooobjectoowithoutooanyoootherooobjectsoooroootherooforcesoosh
own.ooEachooforceooisooshownooonootheoodiagramoobyooaoovector,oowhichooisooanooarrowoo
pointingooinootheoodirectionooofootheooforce.oo(ootheoonormalooforceooisoothatoocomponentoo
ofootheoocontactooforceoothatooisooperpendicularootoootheoosurfaceoothatooanooobjectoocont
acts)
Howootoooresolveooforcesoo(forceoodiagramoosteps)oo-ooCORRECTooANSWERS-
1.ooDecideooonooaooscaleooofooNooperoocm.
2.ooDrawootheoo2oogivenooforces,oogivingoorespectootoootheiroolengthoo(moreoocmooifoomor
eooN)ooandootheooangleoothatooyouooareoogiven
3.ooDrawooaoolineooconnectingootheooendooofootheoo2oootheroolinesootoooformooaootriangle
4.ooMeasureootheoolengthooofoothisooline,oothenooconvertooitootoooNoobyoousingootheooscale
RelationshipoobetweenooJoulesooandooworkoodoneoo-ooCORRECTooANSWERS-
Whenooaooforceoocausesooandooobjectootooomove,ooworkooisoodoneooonootheooobjectoosooo
whenootheooforceoocausesoodisplacement.ooOneoojouleooofooworkooisoodoneoowhenooaoofor
ceooofoo1oonewtonoodisplacesooanooobjectoo1oometre.oo1ooJouleoo=oo1oonewton-metre.
Equationooforoowordoodoneoo-ooCORRECTooANSWERS-
workoodoneoo=ooforceooxoodistance
ElasticooDeformationoo-ooCORRECTooANSWERS-
Whenooanooelasticooobjectooisoostretched,oobent,ootwistedoooroocompressedooitoowillooretur
nootoooitsoooriginalooform
InelasticooDeformationoo-ooCORRECTooANSWERS-
Polyetheneoobagsoowilloonotooreturnootoootheiroooriginalooshapeooafteroobeingoodeformed,o
othisooisooinelastic.
Hooke'sooLawoo-ooCORRECTooANSWERS-
Theooextensionooofooanooelasticooobjectooisoodirectlyooproportionalootoootheooforceooapplie
dooasoolongooasootheoolimitooofooproportionalityooisoonotooexceeded:
Equationooforooforceoo(Hooke'soolaw)oo-ooCORRECTooANSWERS-
forceoo=oospringooconstantooxooextention
Extensionooandoocompression'soorelationshipoowithooelasticoopotentialooenergyooexplanati
onoo-ooCORRECTooANSWERS-
Aooforceoothatoostretchesoooroocompressesooaoospringoodoesooworkooandooelasticoopotenti
alooenergyooisoostoredooinootheoospring,ooprovidedootheoospringooisoonotooelasticallyoodefor
, med,ootheooworkoodoneooandooelasticoopotentialooenergyooareooequal.ooBeforeootheoolimito
oofooproportionalityooisoobreechedootheoorelationshipooisoolinearoo(directlyooproportional)oo
afterwardsooitooisoonon-linear
Elasticoopotentialooenergyooequationoo(given)oo-ooCORRECTooANSWERS-
Elasticoopotentialooenergyoo=oo1/2ooxoospringooconstantooxooextension^2
Momentoomeaningoo-ooCORRECTooANSWERS-
Theooturningooeffectooofooaooforceooisoocalledooitsoo'moment'
Momentooequationoo-ooCORRECTooANSWERS-momentoo=ooforceooxoodistance
Balancingoo-ooCORRECTooANSWERS-
Ifooanooobjectooisoobalancedootheooclockwiseoomomentooisooequalootoootheooanticlockwiseo
omoment.
Leversoo-ooCORRECTooANSWERS-
Aooleverooconsistsooofooaooload,ooeffortooandoopivot,ooleversoouseoomomentsootooomultiplyo
oaooforce,ootheyooallowooaoolargerooforceootoooactooonootheooloadoothatooisoosuppliedoobyoot
heooeffort.
EngineooGearsoo-ooCORRECTooANSWERS-
Engineoogearsoohaveootwooomainoojobs,ooproducingootorqueooandoospeed,oohoweveroothe
yooareooinverselyooproportionaloosooogearsooareoomadeootooomakeooaoocompromiseoobetw
eenootheootwoooinooanyoogivenoosituation.
Whenoostartingooaoocarooweoowantoohighootorque,oowhichoomeansoobeingooableootooocarry
ooaoogreaterooloadoo,ooandooconsequentiallyoolessoospeed.ooInoolowoogearsoothisooisooachi
evedooas...oo-ooCORRECTooANSWERS-
1.ooTheooengineoocausesooaoosmalloocogooonootheooengineooaxleootooorotate.
2.ooTheoosmalloocogooonootheooengineooaxleooisooconnectedootoooaoolargeroocogooonootheo
owheelooaxle,oowhichooincreasesootheootorqueoo(moment)ooexerted.
3.Aoohighooturningooforceoobutoolowoospeedooisooexertedooonootheoowheeloo(lowoogear)
Whenooaoocarooisooalreadyoomoving,ooweoowantooaoohighoospeedoowhichooisooachievedooa
s...oo-ooCORRECTooANSWERS-
1.Theooengineoocausesooaoolargeroocogooonootheooengineooaxleootoooturn.
2.Theoolargeroocogooonootheooengineooaxleooisooconnectedootoooaoosmalleroocogooonootheo
owheelooaxle,oocausingooaoohighoorateooofoorotation,oobutooaoolowooturningooforce.
3.ooTheoowheeloorotatesooquickly,oocausingooaoohighoospeed
