第1題WhichofthetwostructuresshowninthediagramcanmovetheforcealongitslineofactiontotheBCpart()ABothDiagram(a)and(b)BNeitherDiagram(a)nor(b)COnlyDiagram(a)DOnlyDiagram(b)第2題Intheillustratedplanarsystem,ahomogeneoussphereAweighs,andanidealpulleyCandaflexibleropearemaintainedonasmoothslopewithanelevationangleof,withoutconsideringtheirownweightandfriction.OneendoftheropeisattachedtoanobjectBwithaweightof.Thefollowingdrawingoftheforcediagramoftheseparatedbodyisincorrect()ABCD第3題TheverticesA,B,andCoftheisoscelestriangleframeworkABCareallconnectedbyhinges,withthebottomedgeACfixed.ThemidpointDoftheABsideexertsaforceparalleltothefixededgeAC.Withoutconsideringtheweightofthemember,thefollowingforcediagramoftheseparatedbodyisincorrect()ABCD第4題Whichofthefollowingconstraintdiagramsoftheballisincorrect?()ABCD第5題WhichiserrorintheforcediagramofbeamAB()ABCD第6題TheplanarstructureisconnectedbyhingesBandCbetweenAB,BC,andCDthreerods,andothersupportsandloadsareshownintheDiagram.TheforceactsonthemidpointEoftherodCD.Whichofthefollowingforcediagramsofseparationbodyiscorrect()ADiagram(A)BDiagram(B)CDiagram(C)DDiagram(D)第7題Thetriangulararchisshowninthediagram,whichignoresitsweight.Takethewholeastheresearchobject,whichofthefollowingfourdiagramsisthecorrectforcediagram.()ADiagram(A)BDiagram(B)CDiagram(C)DDiagram(D)第8題ThediagramshowsaweightlessstraightrodAB,withendAbeingthefixedendandendBbeingtherollersupport.Whichofthefollowingfourfiguresisthecorrectforcediagram.()ADiagram(A)BDiagram(B)CDiagram(C)DDiagram(D)第9題Thediagramshowsthestructureofthemembers.ABandCDareconnectedbyahingeatpointE,ABishingedtothehorizontalrodGBatpointB,BGisinsmoothcontactwiththerodCDatpointD.Theweightofeachmemberisignored,andaverticaldownwardforceactsatpointG.Whichofthefollowingfourdiagramsisthecorrectforcediagramfortheselectedresearchobject.()ADiagram(A)BDiagram(B)CDiagram(C)DDiagram(D)第1題Aconcurrentforcesystem:,withdirectionsasshowninthefigure,theresultantforceoftheforcesystemis()A124NB166NC231ND75N第2題Intheillustratedsystem,forcesandactatnodeCofropesABandBCinthedirectionshowninthefigure.Given,inordertomaintaintensionbetweenthesetworopes,therangeofforceis()ABCD第3題TheillustratedframeworkconsistsofABandBC,withhingesatpointsA,B,andC.TheweightofthesuspendedheavyobjectatpointBis,andtheweightoftherodsareignored.TheinternalforceofrodABis()ABCD第4題Intheillustratedoverhangingbeam,thediagramThemagnitudeoftherestrainingforceatsupportBis()ABCD第5題IfaforcecouplewithamagnitudeofactsonarightangledcurvedrodADB,thentherestrainingforceatsupportAis()ABCD第6題IfaforcecouplewithamagnitudeofactsonarightangledcurvedrodADB,thentherestrainingforceatsupportAis()ABCD第7題Theplanarsystemissubjectedtoaforcecoupleofmagnitudeof.WhentheforcecoupleactsontherodAC,themagnitudeofthereactionforceonthesupportAis()ABCD第8題ThepointBoftherigidframeexertsahorizontalforce,andtheweightoftherigidframeisignored.Therefore,themagnitudeofrestrainingreactionforceatsupportDis()ABCDAssignmentS3第1題ThesupportandstressconditionsofsimplysupportedbeamABareshowninthediagram.Giventheconcentrationofthedistributedload,themagnitudeofthecouplingmoment,andthespanofthebeamis.Withoutconsideringtheweightofthebeam,therestrainingforceatsupportBis()ABCD第2題Usingaclawhammertopullanail,whichofthefourforcesshowninthefollowingfigureistheleastforce.()AFigure(A)BFigure(B)CFigure(C)DFigure(D)第3題ThemomentequationoftheforcesystemactingonthebeamaboutpointAis()ABCD第4題,ThemomentoftheconstraintcoupleonpointAis()AB0CD第5題.ThemagnitudeofconstraintforceonpointBis()A18.1kNB20kNC10kND19.2kN第6題ThelengthofthebeamThemagnitudeofconstraintforceonpointAis()A15kNB0C35kND20kNAssignmentS4第1題Thesupportsituationandloadofthehorizontalcompositebeamareshowninthediagram.Given.ReactionforceatsupportEwhenbeambalanceis()A200NB250NC300ND350N第2題Intheillustratedmechanism,,Theradiusofthepulleyis.Takethehorizontaldirectionasthex-axis.GiventheweightofobjectEis,whenthesupportisbalanced,theconstraintreactionforceatsupportAis()ABCD第3題Intheillustratedmechanism,AandBarerespectivelyfixedhingesupportsandmovablehingesupports,andDisahingeconnection.Given,withoutconsideringtheselfweightofcomponents,theinternalforceofrodBCis()

ABCD第4題Thecompositebeamiscomposedoftwosections,ACandCD,hingedatC,andthesupportingandstressconditionsareshowninthefigure.Givenauniformlydistributedloadconcentration,themagnitudeofthecouplemoment.Withoutconsideringtheselfweightofthebeam,thereactionforceatsupportBis()A20kNB30kNC40kND50kN第5題BracketABCconsistsofrodsAB,AC,andDH,withdimensionsasshowninthediagram.DofthehorizontalrodDHishingedtotherodAB,whilethepinEatthemidpointofDHcanslidefreelyintheslotoftherodAC,exertingaverticalforceatthefreeend.TherestrainingforceofthesupportCis()ABCD第6題TheplanarstructureconsistsofthreerodsAB,BC,andCDconnectedbyhingesBandC.Othersupportsandloadsareshowninthediagram.ForceactsonthemidpointEoftherodCD.Giventheselfweightofeachrodisnotconsidered.ThemagnitudeofrestraintmomentatfixedendAis()ABCD第7題Whichofthefourstructuresshowninthediagramisstaticallyindeterminate()ADiagram(A)BDiagram(B)CDiagram(C)DDiagram(D)第8題TheillustratedstructurehasanequilibriumequationforthemomentofpointA,whichis()ABCD第9題Theillustratedmechanism,withthewholeastheobject,hasanequilibriumequationforthemomentofthepointO()ABCDAssignmentS5第1題Thefrictionanglebetweenanobjectandahorizontalplaneis.Theobjectisaffectedbytwoforces,and,and.Thestateoftheobjectis()AStaticBCriticalequilibriumCSlidingDIt’suncertain.

第2題Ablockweighingisplacedonaslopewithaninclinationangleof,andthefrictionanglebetweentheblockandtheslopeis,thenthestateoftheblockis()AStaticBSlidingdownwardCCriticalequilibriumDIt’suncertain.第3題IfblocksAandBarestackedonahorizontalplaneandbothblocksweigh,theappliedforceis.IfthefrictioncoefficientbetweentwoblocksandbetweenblockBandthehorizontalplaneis,then()AAmoves,Bdoesn'tmoveBB

moves,Adoesn'tmoveCNeitherAnorBmovesDBothAandBmove第4題AblockweightsP.AhorizontalforceFissubjectedtoit.Given,thefrictionangleis,then()ATheobjectslidesupwardsBStaticCCriticalequilibriumDTheobjectslidesdownwards第5題AssumingthemaximumfrictionforcebetweenblockAandBis,andthemaximumfrictionforcebetweenblockBandthegroundCis.Forthefollowingsituations,areblocksAandBstationaryorsliding?Giventhat,then()AAmoves,Bdoesn'tmoveBBmoves,Adoesn'tmoveCNeitherAnorBmovesDBothAandBmove第6題AssumingthemaximumfrictionforcebetweenblockAandBis,andthemaximumfrictionforcebetweenblockBandthegroundCis.Forthefollowingsituations,areblocksAandBstationaryorsliding?Giventhat,then()AAmoves,Bdoesn'tmoveBBmoves,Adoesn'tmoveCNeitherAnorBmovesDBothAandBmove第7題TheweightofthewoodenladdershowninthediagramisP.TheendBisleaningagainstaverticalwall,andtheendAisplacedonahorizontalground.Ifthegroundisabsolutelysmooth,thereisfrictionbetweenthewoodenladderandthewall,withafrictioncoefficientoff.Theanglebetweentheladderandthegroundisα.Whichofthefollowingfourstatementsiscorrect.()AIf,theladdercanbalanceBIf,theladdercanbalanceCOnlywhentheladderisunbalancedDWhen,theladderremainsunbalanced第8題Theweightoftheblockshowninthediagramis,withaforceof.Thefrictionangleofthegroundis,andtheslidingfrictioncoefficientis0.18.Themagnitudeofthefrictionalforceis()A3kNB4kNC5kND3.6kN第9題Theheightofahomogeneousrectangularprismis,thewidthis,andtheweightis.Whenplacedonaroughhorizontalplane,ithasastaticslidingfrictioncoefficientwiththehorizontalplane.Tomaintainbalanceofanobject,themaximumhorizontalforceactingonitis()A200NB240NC600ND300N第10題Theweightoftheblockshowninthediagramis,withaforceof,andthestaticfrictioncoefficientwiththegroundis0.2.Themagnitudeofthefrictionalforceis()ABCD正確答案：BCAssignmentK1第1題Whenapointmovesinacurvedmotion,themagnitudeofitsaccelerationanditsprojectiononthesecondarynormalaxisare()ABCDmaybe正確答案：BC第2題Giventhatthemovingpointmovesinauniformcircularmotionwithavelocityof4m/sandaradiusRof0.5m,themagnitudeofthetotalaccelerationis()A16m/s2B32m/s2C64m/s2D128m/s2第3題Ifapointmovesaccordingtothepatternof(sisinmeters,tisinseconds),when,thedistancetraveledatthatpointis()A8mB10mC18mDAvalueoutsideof8m~18m第4題Ifthemotionequationoftheknownpointis,thenitspathequationis()ABCD第5題Apointmovesinacurve,thevelocityatthebeginningis,thetangentialaccelerationatacertainmomentis,themagnitudeofthevelocityofthatpointattheendof2secondsis()A2m/sB18m/sC12m/sDIt’sunabletodetermine第6題Asshowninthefigure,thesmallringstartsmovingalongthepathfromAwhenitisstationary.InsegmentAB,theaccelerationisa=g,andinsegment,thetangentialaccelerationis,.TheaccelerationoftheringatpointCis()A4gB0CgD2g第7題Asshowninthefigure,thelengthofrodABislanditrotatesaroundpointBatequalangularvelocity,withtherotationequationis.AndthesliderBconnectedtotherodABvibrateshorizontallyaccordingtoaregularpattern,whereaandbareconstants,andthepathofpointAis()ABCD第8題ThelengthoftheellipticalrulerBCis2l,thelengthofthecrankOAisl,AisthemidpointofBC,MisapointonBCandMA=b,asshowninthefigure.ThecrankOArotatesaroundtheOaxisatequalangularvelocity,andwhenthemotionbegins,thecrankOAisinaverticalposition.ThepathequationforpointMis()ABCD第9題PutasmallringontheironringwitharadiusofR,andinserttherodABintothesmallringM,itrotatescounterclockwisein(isconstant)aroundtheAaxisontheironring.Theironringisfixedinplace,asshowninthefigure.WhichofthefollowingstatementsiscorrectaboutthespeedofthesmallringM?()AAtt=0,thevelocityofthesmallloopisBAtanygivenmoment,thespeedofthesmallloopisCAtt=0,thevelocityofthesmallloopis0DAtt=0,thevelocityofthesmallloopisAssignmentK2第1題Iftheangularvelocityandangularaccelerationofafixedaxisrotatingrigidbodyatacertainmomentarebothalgebraicquantities()AWhen,rigidbodyperformsacceleratingrotationBAslongas,therigidbodymustperformdecelerationmotionCWhen,therigidbodyperformsdecelerationmotionDWhen,therigidbodyperformsdecelerationmotion第2題Arightangledrodrotatesaroundafixedaxis,andatthemomentofrotationshowninthediagram,itsangularvelocityisandangularaccelerationis.Theirdirectionsareshowninthediagram.Whichofthefollowingfourdiagramsiscompletelycorrectregardingthedirectionofvelocity,tangentialacceleration,andnormalaccelerationatpointBontherod()ABCD第3題Thediagramshowsacarpassingthroughanintersection.DuringtheturningprocessfromAtoB,ifthevelocitiesofCandDattherearofthecarareknowntobeand,andthedistancebetweenCandDis,inthatcasetheangularvelocityofthecarrotatingaroundthefixedaxisOis()ABCD第4題Intheillustratedmechanism,itisknownthatO1A=O2B=AC=,O1O2=AB=,ThecrankO1Arotatesclockwiseatauniformangularvelocity.Wheninthepositionshowninthediagram,pointsO1,A,andCarelocatedonthesamestraightline,andpointEisthemidpointofAB.Therefore,whichofthevelocitiesandaccelerationsofpointsCandEshownbelowiscorrect(

)ABCD第5題Aplatformscalemechanismisshowninthediagram,whichincludesleverAC,scaleplatformABD,weightC,weightM,andsupportrodO2B.ItisknownthatO1A=O2B=O1O2=AB,O1C=.ThedistancefromthecenterofgravityofweightMtoABis.Iftheweightobtainsadownwardvelocity,thenthemagnitudeoftheweight'svelocityis()ABCD第6題Whenthefour-barlinkagemechanismmovestothepositionshowninthediagram,AB∥O1O2,theangularvelocityofrodO1Ais,andtherodlengthisl.Therefore,theangularvelocityofrodO2Bis()ABCD第7題Athinropeiswoundaroundthepulley,andthereisnorelativeslidingbetweentheropeandthepulley.AblockAistiedtotheendoftherope,asshowninthediagram.TherelationshipbetweenthevelocityandaccelerationofthepointBontheedgeofblockandthepulleyAis()A,B,C,D,第8題TheliftingmechanismconsistsofgearsA,B,anddrumD.DrumDisfixedtogearB,withradiir1=2R,r2=3R,r3=R.Giventhattheaccelerationoftheweightrisingatacertainmomentisa,theangularaccelerationofgearAatthismomentis(

)ABCD第9題Intheinstrumentstructureshowninthediagram,thenumberofteethforgears1,2,3,4isrespectively6,24,8,32,Theradiusofgear5is5cm.IfrackBmoves1cm,theanglethatpointerArotatesis()A3.2radB0.2radC0.8radD1.6rad第10題Intheillustratedmechanism,O1A=O2B=r,O1O2=AB=2r.ABCDisarigidgiantboard,AC=r,ThemotionpathofpointConthegiantboardis(

)AStraightLineBEllipseCAcirclewitharadiusof2rDAcirclewitharadiusofrAssignmentK3第1題Intheillustratedmechanism,thediskrotatesanticlockwisearoundaxisOataconstantangularvelocity.IfpointAonrodABistakenasthemovingpointandthemovingsystemisselectedtobefixedtothedisk,whichofthefollowingfourdiagramsisthecorrectparallelogramforthemovingpointvelocity?()ABCD第2題Thesemi-circularplatesAandBintheillustratedmechanismareconnectedbyhingestotwoparallelrodsofequallength.TheparallelrodsO1AandO2BrotatearoundtheaxesO1andO2atauniformangularvelocity,respectively.AsmallpulleyCisinstalledontheverticalguiderod,whichiscloselyattachedtothesemi-circularplateandslidesrelativetoitalongthecircumferenceofthesemicircle,causingtheguiderodtotranslateupanddownintheverticalslide.IfpulleyCisusedasthemovingpointandsemi-circularplateABisusedasthemovingsystem,analyzethevelocityofpulleyCatthepositionshowninthediagram.Whichofthefourvelocityquadrilateralsdrawnbelowiscorrect?()ABCD第3題AsmallringisplacedonanironringwitharadiusofR,andanotherrodABisinsertedintothesmallringMandrotatedcounterclockwise(constant)aroundtheAaxisontheironring.Theironringisfixed,asshowninthediagram.When,thespeedofthesmallringMis()ABCD第4題Asshowninthediagram,asleeveishingedatpointConthediscandfittedontotherockerAB,therebydrivingtherockertomove.Whenintheillustratedposition,,,.Atthattime,theangularvelocityofthejoystickABis()AB0C4D2第5題Thediagramshowsaneccentriccam-topplatemechanism.ThecamrotatesatanequalangularvelocityaroundpointO,witharadiusofRandaneccentricityofOC=.Theinstantaneousangleshowninthediagramis=30°.Therefore,thevelocityofthetopplateis()A0BCD第6題Asshowninthediagram,theslidermoveshorizontallytotherightataconstantspeedanddrivestherockerOAtorotatearoundtheOaxisthroughthesliderpinB.TheinstantaneousvelocityofpinBrelativetojoystickOAinthediagramis()Av0BCD第7題GiventhatO1O2hasthelengthofandOArotatesaroundOatauniformangularvelocity,ifAisthemovingpointandO2Bisthemovingsystem,when,therelativevelocityofAis(),andthetransportvelocityis()ABC0,D,第8題RodOAhasthelengthof.ItrotatesaroundpointOonthedrawingsurfacebybeingpushedbyapushrod,asshowninthediagram.Assumingthevelocityofthepushrodisanditselbowheightis.CalculatethemagnitudeofthevelocityattherodendA(expressedasafunctionof).()ABCD第9題TherightangledcurvedrodOBCinthediagramrotatesaroundtheOaxis,causingthesmallringMfittedonittoslidealongthefixedstraightrodOA.Given:OB=0.1m,OBisperpendiculartoBC,theangularvelocityofthecurvedrodisrad/s.When=60o,thevelocityofthesmallringMis()A0B1m/sC2m/sDm/s第10題Intheillustratedmechanism,AB=CD=EF=l,Whensetattheillustratedposition,,theangularvelocityofrodEFis,thentheangularvelocityofrodABatthistimeis()AB/2C0D2第11題Asshowninthediagram,themechanism,O1A=O2B=r=10cm,O1O2=AB=20cm.Whenintheillustratedposition,theangularvelocityoftheO1Arodis,theangularaccelerationis,andtherodsOlAandEFarelocatedonthesamehorizontalline.TheEendoftheEFrodisincontactwiththeedgeBDofthetriangularplateBCD.TheinstantaneousaccelerationoftherodEFrelativetothetriangularplateBCDshowninthediagramis()A10cm/s2Bcm/s2C5cm/s2Dcm/s2第12題Thecarmovesinastraightlineatauniformvelocity,andtheflywheelonthecarrotatesatauniformangularvelocity(theradiusis).IfMistakenasthemovingpointandthecaristhemovingcoordinatesystem,theinstantaneousaccelerationatpointMinthediagramis()ABC0D第13題Intheillustratedplanarmechanism,O1A=O2B=100mm,O1A∥O2B,O1ArotatesaroundaxisO1atanequalangularvelocityof.ThereisasleeveConrodAB,whichishingedtorodCD.Allcomponentsoftheorganizationareinthesameverticalplane.When,theaccelerationoftherodCDis()A0.4m/s2Bm/s2C0.2m/s2D0.3m/s2第14題Asshowninthediagram,asleeveishingedatpointConthediscandfittedontothejoystickAB,therebydrivingtherockertomove..Whenintheillustratedposition,,,.Atthistime,theangularaccelerationofthejoystickABis()A3.2B0C9.24D2AssignmentK4第1題Whenthemechanismisinthepositionshowninthediagram,theangularvelocityofABrodrotationis,theangularaccelerationis0,ABandGCarevertical,BandEhingesarelocatedonthesamehorizontalline,AB=BE=EC=ED=r.Atthistime,therelativeaccelerationofsliderDslidingintheGCrodslotis()ABCDThedirectionofisverticalupwards第2題IftheinstantaneousvelocitycenterofaplanarshapeispointC,andthevelocityandaccelerationatthatpointarerepresentedbyand,respectively,then()AMust,B,CMaybe,DThedistributionpatternofvelocityandaccelerationateachpointontheplanargraphisthesameaswhenitrotatesaroundthefixedaxisC第3題Asshowninthediagram,adiscwitharadiusofRrollsalongthehorizontalplaneatauniformangularvelocitywithoutsliding.TheendAoftheABrodishingedtotheedgeofthedisc,anditsendBslidesonthehorizontalplane.Whenintheillustratedposition,themagnitudeoftheaccelerationattheendBis()ABCD第4題Whenthemechanismisinthepositionshowninthediagram,theangularvelocityoftherodOAis,theangularaccelerationis0,theinclinationanglesoftherodsOA,BC,andCDareall45°,andtherodDEisvertical.Giventhat,,themagnitudeofvelocityofpointDatthistimeis()ABCD第5題Asshowninthediagram,acircularwheelwitharadiusofRrollsatauniformangularvelocityonahorizontalplanewithoutsliding.Whenintheillustratedposition,therodishorizontalandtheinclinationangleoftherodis45°.Giventhat,theangularvelocityoftherodatthistimeis()ABCD第6題Atacertainmomentduringthemotionofthedoublesliderrockermechanism,itislocatedatthepositionshowninthediagram.Atthistime,themagnitudeofvelocityofpointsA,B,andCarerepresentedby,and,respectively,andthemagnitudeofangularvelocityofthetworodsACandBCarerepresentedbyand,respectively.If,,thenthereare()ABCD第7題Asshowninthediagram,sliderAslidestotherightwithinthehorizontalgroove,andtherollerCwitharadiusofrisdrivenbyguiderodABandconnectingrodBCtorollonthehorizontalplanewithoutsliding.GuiderodABcanslidewithinthesleevethatcanrotatearoundtheOaxis,andpointsCandOarelocatedonthesamehorizontalline.Whenintheillustratedposition,,,theanglebetweentherodABandthehorizontallineis60°.Atthispoint,thevelocitiesofpointsA,B,andCarerepresentedby,,.Inthatcase,thereare()ABCD第8題Asshowninthediagram,sliderAslideshorizontallytotherightataconstantvelocity,rodEFmovestotherightalongthehorizontalguidegrooveataconstantvelocity,androdCDmovesintheverticalgroove.Whenintheillustratedposition,theinclinationangleoftheABrodis30°,AC=CE=10cm,Atthistime,thevelocityoftheCDleveris()ABCD第9題Whenthemechanismshowninthediagramisintheillustratedposition,theangularvelocityandangularaccelerationoftherodarerespectivelyrepresentedbyand,andtheangularvelocityandangularaccelerationoftherodarerespectivelyrepresentedbyand.Ifisknown,thereare()AWhen,,BWhen,,CWhen,,theangularaccelerationoftherodisDWhen,,theaccelerationofpointandareequal正確答案：AC第10題Asshowninthediagram,atacertainmoment,thevelocitiesofanytwopointsAandBontheplanegraphareand,respectively..Inthatcase,thevelocityofpointConthelineconnectingthesetwopointsanditsvelocityrelativetopointArespectivelyare()ABCD正確答案：BDAssignmentD1第1題Themassofaparticleis,anditfallsfreelyfromaheightabovetheground.Theairresistanceitexperiencesisassumedtobeproportionaltothefirstpowerofitsvelocityas,whereistheproportionalitycoefficient.Drawtheforcediagramoftheparticleatageneralpositionasshowninthefigure,andtheaxisisverticallyupwards.Thedifferentialequationofitsmotionis()ABCD第2題Asshowninthefigure,themassesofthethreeblocks,,andareall,therigiditycoefficientsofthethreespringsareall,andthestaticequilibriumpositionofeachblockistakenasthecoordinateorigin.Therefore,themotiondifferentialequationformofthethreeblocksis()A,aresame,buttheyaredifferentfromB,aresame,buttheyaredifferentfromCAllthesameDAllthedifferent第3題Asshowninthefigure,theweightsofthetwoblocksandrespectivelyareand,suspendedbyaropespanningoverafixedpulley.Giventhat,theweightofthefixedpulleyisignored,thetensionoftheropeis()ABCD第4題Themassofthesmallringis,whichisfittedontoasmoothsteelwire.Theequationforthesteelwireis(whereisaconstant,andthecoordinatesystemisshowninthefigure).Whenthesmallringslidesfreelyfromtothelowestpointofthesteelwire,theconstraintreactionforceofthesteelwireonthesmallringis()ABCD第5題Theweightoftheblockshowninthediagramis,whichmovesinastraightlinealongahorizontalsmoothsurfaceundervariableforce,measuredinsecondsandmeasuredinnewton.Theinitialvelocityoftheblockis,andthedirectionofforceisthesameasthedirectionofvelocity.Thedistancetraveledbytheobjectwithin4secondsfromthebeginningofitsmovementis()ABCDAssignmentD2第1題A24kgbulletisfiredfromthemuzzleataspeedof500m/s,withabarrellengthof2m.Theaveragepressureoftheexplosivegasonthebulletis()A750kNB1500kNC3000kND4500kN第2題Asthetrainapproachesthestationatavelocityof10m/s,ittravelsdownaslopewithagradientofα=0.008rad.Atacertainmoment,thedriverbeginstobrake,andtheresistancegeneratedbythefrictionofthebrakewheelaxleisequalto0.1timestheweightofthevehicle.Assumingsinα=α,thebrakingtimeis()A11.8sB15.0sC22.3sD30.5s第3題Amathematicalpendulumwithalengthoflmovesawayfromtheequilibriumpositionatahorizontalinitialvelocityofv0.thearclengthitspanswithinonecycleis()。As=2larccos?(1?v022gl)Bs=4larccos?(1?v022gl)Cs=3larccos?(2?v022gl)Ds=2larccos?(2?v022gl)第4題TwowheelsareconnectedtotheparallelrodABofthesteamenginethroughrodO1O2.ThemassofthewheelsisM1,andthemassoftheparallelrodABandtheconnectingrodO1O2isM2.Assumingthatthemassofthewheelsisdistributedalongtheedges,O1A=O2B=r/2,Whereristheradiusofthewheel.Thewheelsrollpurelyonastraighttrack,andthespeedofthewheelaxleisv0.Requestthekineticenergyofthissystem.()AT=v024[16M1+M2(9+sin?φ)]BT=v024[8M1+M2(9+sin?φ)]CT=v028[16M1+M2(9+sin?φ)]DT=v028[8M1+M2(9+sin?φ)]第5題Acylindricalshaftwithadiameterof10cmandamassof0.5tisequippedwithaflywheelwithadiameterof2mandamassof3t.Theflywheelrotatesatanangularvelocityof60r/minatacertainmomentandthenrotatesfreelythereafter.Thefrictioncoefficientofthebearingis0.05,andthemassoftheflywheelcanbeseenasdistributedonthewheelrim.Howmanyrevolutionsdidtheflywheelmakebeforestopping?()A98.7rB150.5rC203.8rD109.8r第6題TherodABhasthelengthof2a.Duringtheprocessoffalling,thelowerendAslidesalongthesmoothhorizontalplane.Theinitialinstantaneousrodisinaverticalpositionandstationary.Trytoexpressthevelocityoftherodcenterasafunctionoftheheighthfromthefloor.()A

v=(a?h)6g(a+h)8a2?3h2Bv=(a?h)6g(a+h)4a2?3h2Cv=2(a?h)3g(a+h)4a2?3h2Dv=(a?h)3g(a+h)4a2?3h2AssignmentD3第1題Theparticlemovesuniformlyalongthecircumferenceatavelocityof=0.2m/sandcompletesoneorbitin=4s.Letthemassoftheparticlebe=5kg,andcalculatetheimpulseoftheforceactingontheparticleduringthehalfcycle.()ABCD