雨课堂学堂在线学堂云《Engineering Mechanics（西北工业）》单元测试考核答案

第1题CanwemoveforceFfromACtoBCinthefollowingfigurealongitsactionline?()ABothBbCaDNeither第2题Whichforcediagramiswrong?TheweightofAandBareW1andW2.ThepulleyChasnoweight.()ABCD第3题Whichforcediagramiswrong?()ABCD第4题WhichforcediagramofbeamABiswrong?()ABCD第5题Whichforcediagramisright?()ABCD第6题Whichforcediagramisright?()A(A)B(B)C(C)D(D)第7题Whichforcediagramisright?()A(A)B(B)C(C)D(D)第1题TheprojectionofforceFonxandyaxisare()A,B,C,D,第2题F1=150N,F2=80N,F3=140N,F4=50N,themagnitudeoftheresultantforceoftheconcurrentforcesystemis()A124NB166NC231ND75N第3题Q=534N.TherangeofthetensionforcePtoensurethestringACandBCtosustaintensionforceare()AP<580NBP<668NC290D290第4题ThegravityoftheloadisG,neglectingtheweightofthebarABandBC.TheinternalforceinthebarABis()A0.5GB0.75GC0.87GD1.2G第5题Thisisapressesmodulediagram,whichcanpressthebodyEbyactingaforcePonpointB.P=300N,DeterminethepressureforceonthesideofthebodyE,neglectingthefrictionandtheweightofallthememberinthesystem.()AAbout900NBAbout1000NCAbout1100NDAbout1200N第6题DetermingtheconstraintforceonpointB(())AQl/aBQa/lCQ(l-a)/lDQ(l-a)/a第7题ThereisaforcecoupleofmomentLactingontherightanglebarADB.DetermingtheconstraintforceonpointA()AL/(4a)BL/(3a)CL/(2a)DL/a第8题ThereisaforcecoupleofmomentLactingontherightanglebarADB.DetermingtheconstraintforceonpointA()AL/(4a)BL/(3a)CL/(2a)DL/a第9题TherivetedsheetissubjectedtothreeforcesatholecentersA,B,andC,asshowninthefigure.F1=100N,F2=50N,F3=50N,theresultantforceofthisforcesystemis()A141NB151NC161ND171N第10题Thefour-linkmechanismABCD,BandCaresmoothhinges,andAandDarefixedhingedsupports,whichareactedbythetwoforcesPandQshowninthefigure.Ifthemechanismistobebalancedinthepositionshown,thereis()AP=-0.61QBP=1.22QCP=0.61QDP=0.707Q第11题Regardlessoftheweightofthestraightrodshowninthefigure,bothendsofthehingeareconnectedwithAslidingblockAandBwhichcanslideinsmoothhorizontalandverticalchutes.IfaforceisappliedatthemiddlepointCofthethinrod,P>0.Whichofthefollowingfourforcescausestherodtoequilibrate?()A图(C)B图(A)C图(B)D图(D)第12题ThemidpointEoftheABrodisfixedwithapin.ThepincansliderelativelyinthesmoothstraightgrooveoftherodCD.IfthepinislocatedatthemidpointoftherodCDandaweightPishungattheDend,themechanismisinequilibriumunderthehorizontalforceQ,thenthereis()AP=QBRC=PCRA=QDRE=Q第13题Here,theAnglebetweenthesystemrodandthesmoothstraightwallisθ.ABisahomogeneousrodrestingonafixedsmoothroundpinC.Whichofthefollowingstatementsistrue?()A能使杆AB平衡的θ值是唯一的B能使杆AB平衡的θ值不是唯一的,而是有某一个范围C任何的θ值都不能使杆AB平衡D只要AB杆的重心在销子C的外侧,则任意小于90º的θ值都能使杆AB平衡第14题Themagnitudeofaforceis60kN,themagnitudeofitscomponentforceonthexaxisis30kN,andtheAnglebetweentheforceFandthexaxisis()A60°B夹角无法确定C30°D90°第15题IfthebendingbarhasnoweightandactsonacoupleofmomentM,thereactionatpointBinFigure()isgreaterthanthereactionatfigure()()A大B小C相同D条件不足,不能确定第16题There’saforcecoupleofmomentMactingonthebarAC.M=10KN.m.DetermingtheconstraintforceonpointA()A4K;B5KNC8KND10KN第17题There’saforceFactingonpointB.DetermingtheconstraintforceonpointD()AFD=0.5FBFD=1.0FCFD=1.5FDFD=2.0F第18题Whichoneoftheprojectionoftheforcesonxaxisareright?()AF1x=F1cosα1BF2x=F2sinα2CF3x=F3cos(180°+α3)DF4x=F4sinα4正确答案：CD第19题Whichoneoftheprojectionoftheforcesonyaxisareright?()AF1y=-F1cosα1BF2y=-F2cosα2CF3y=-F3cos(180°+α3)DF4y=F4cosα4正确答案：AD第20题Thedeadweightofeachbarinthemechanismshownisignored.Whichoftherodsaretwo-forcemembers?()AOA是二力构件BABC是二力构件CBE是二力构件DCD是二力构件正确答案：CDChapter3assignment第1题Iftheplaneforcesystemconsistsofthreeforces(assumingthethreeforcesarenotparallel),whichofthefollowingstatementsistrue?()AIfthesystemofforcesisreducedtoapointandtheprincipalmomentiszero,thenthethreeforcesmustconvergeatonepointBIftheprincipalvectoriszero,thenthethreeforcesmustconvergeatonepointCThisforcesystemmustnotbereducedtoanetpairDIfthreeforcesdonotconvergeatonepoint,theforcesystemmustbeunbalanced第2题FourforcesareappliedonthreepointsA,BandCofOABC,Asquareplatewithsidelengtha=2m:F1=3kN,F2=5kN,F3=6kN,F4=4kN.Whatisthefinalresultofthisforcesystem?()AanetforceandanetcoupleBaresultantforceCanetcoupleDforcesysteminequilibrium第3题ThebearingandstressofsimplysupportedbeamABareshowninthefigure.Theknownsetofthedistributedloadq=20KN/m,themagnitudeofthemomentofthecoupleM=20KN•m,thespanofthebeaml=4m.Excludingthedeadweightofthebeam,thebindingforceatsupportBis()A12KN;B14KN;C17KN;D21KN第4题F1=F2=20kN,AC=DB=2m,AB=7m.ThemagnitudeofconstraintforceonpointBis(())A18.1kNB20kNC10kND19.2Kn第5题F=20kN,M=40kN·m.ThelengthofthebeamAB=4m.AC=1m.ThemagnitudeofconstraintforceonpointAis()A15kNB0kNC35kND20kN第6题M=qa2,ThemomentoftheconstraintcoupleonpointAis()AMA=qa2B0CMA=0.5qa2DMA=2qa2第7题Thesystemofcompositebeamisshowninthefigure.P=500N,q=250N/m,m=500N·m.TheconstraintforceonpointEis()A200N;B250N;C300N;D350N第8题Thesystemofbracketisshowninthefigure.AB=AC=CD=1m,theradiusofthepulleyisr=0.3m.TheweightofloadEisW=100KN.TheconstraintforceonpointAis()AFAx=230KN,FAy=100KN;BFAx=100KN,FAy=230KN;CFAx=200KN,FAy=230KN;DFAx=230KN,FAy=200KN第9题ThesystemofbracketisfixedhingesupportonpointAandkinetichingesupportonpointB.TheweightofloadQisQ=12KN.TheinternalforceinthebarBCis()A12KN;B13KN;C14KN;D15KN第10题ThesystemofcompositebeamisconsistofACandCDshowninthefigure.q=10kN/m,M=40kN·m.TheconstraintforceonpointBis()A20KN;B30KN;C40KN;D50KN第11题Thesystemofbracketisshowninthefigure.TherodDHispinconnectedwithrodAB,andthereisanactiveforceFactingonpointH.ThepinEisfixedonDHanditcanslidealongtheslotofAC.Neglecttheweightofalltherods.DeterminetheconstraintforceonpointCwhenthissystemisbalanced.()A.FCx=F,FCy=F;BFCx=2F,FCy=F;CFCx=F,FCy=2F;DFCx=2F,FCy=2F第12题ThesystemofbracketisconsistedoftherodAB,BCandCDwhicharepinconnectedeachother.ThereisanactiveforceFactingonthemiddlepointEofrodCDandauniformforceqactingonBC.F=8kN,q=4kN/m,a=1m.Neglecttheweightofalltherods.DeterminetheconstraintmomentonpointAwhenthissystemisbalanced.()AMA=10kN·m;BMA=12kN·m;CMA=14kN·m;DMA=16kN·m第13题Iftheplaneforcesystemconsistsofthreeforces(assumingthethreeforcesarenotparallel),thefollowingstatementistrue.()AIfthesystemofforcesisreducedtoapointandtheprincipalmomentiszero,thenthethreeforcesmustconvergeatonepointBIftheprincipalvectoriszero,thenthethreeforcesmustconvergeatonepointCThisforcesystemmustnotbereducedtoanetpairDIfthreeforcesdonotconvergeatonepoint,theforcesystemmustbeunbalanced第14题Usingaclawhammertopullanail,whichofthefourforcesshowninthefollowingfigureistheleasteffort.()A图(C)B图(A)C图(B)D图(D)第15题Thefigureshowsaforcesystemintheplane,F1=F2=F3=F4=F.Thesimplifiedfinalresultofthisforcesystemis.()ATheresultantforcethroughOBAcoupleofforcesCBalanceDNetforcethroughpointA第16题Thefigureshowsfourequalandperpendicularplanearbitraryforcesystemsactingonarigidbody,F1=F2=F3=F4=F,andthefinalsimplifiedresultis()ATheresultantforcethroughOBAcoupleofforcesCBalanceDNetforcethroughpointA第17题Thefigureshowsfourequalandperpendicularplanearbitraryforcesystemsactingonarigidbody,F1=F2=F3=F4=F,andthefinalsimplifiedresultis()ATheresultantforcethroughOBAcoupleofforcesCBalanceDNetforcethroughpointA第18题Thefigureshowsfourequalandperpendicularplanearbitraryforcesystemsactingonarigidbody,F1=F2=F3=F4=F,andthefinalsimplifiedresultis()ATheresultantforcethroughOBAcoupleofforcesCBalanceDNetforcethroughpointA第19题Hereisarigidbodyinequilibriumunderasystemofplanarconfluenceforces.Whichofthefollowingfoursetsofequilibriumequationsisnotindependent()A,;B,;C,;D,

第20题Figurearigidbodyinequilibriumunderaplanesystemofparallelforces.Whichofthefollowingfoursetsofequilibriumequationsisnotindependent()A,;B,;C,;D,第21题Figurearigidbodyinequilibriumunderaplanesystemofparallelforces.Whichofthefollowingfoursetsofequilibriumequationsisnotindependent()A,,B,,C,,D,,第22题Figurearigidbodyinequilibriumunderaplanesystemofparallelforces.Whichofthefollowingfoursetsofequilibriumequationsisnotindependent()A,,B,,C,,D,,第23题Whichoneisstaticallyindeterminateproblem?()A图(C)B图(A)C图(B)D图(D)第24题Whichoneisstaticallyindeterminateproblem?()A图(C)B图(A)C图(B)D图(D)第25题ThemomentequationoftheforcesystemactingonthebeamaboutpointAis()ABCD第26题第27题第28题第29题Chapter4assignment第1题()A(A)B(C)C(D)D(B)第2题()A200NB250NC300ND350N第3题()A(C)B(A)C(D)D(B)第4题()A(A)B(B)C(C)D(D)第5题()A(A)B(B)C(C)D(D)第6题()A12kNB13kNC14kND15kN第7题()A20kNB30kNC40kND50Kn第8题()AMA=10kN·mBMA=12kN·mCMA=14kN·mDMA=16kN·m第9题()AFcx=F,Fcy=2FBFcx=2F,Fcy=2FCFcx=2F,Fcy=FDFcx=F,Fcy=FChapter5assignment第1题()AKeepstatic.BInthecriticalbalancestate.CSliding.DIndeterminate.第2题()AKeepstatic.BInthecriticalbalancestate.CSliding.DIndeterminate.第3题()AAissliding.Bkeepstatic.BBissliding.Akeepstatic.CBotharemovingtogether.DBothAandBkeepstatic.第4题()AMovingupward.BKeepstatic.CInthecriticalbalancestate.DMovingdownward.Chapter6Assignment第1题Asshowninthefigure,thedashedlinerepresentstheshapeoftheelementafterdeformation,thentheshearstrainoftheelementis().AααBπαπ2−αCα2αDπαπ2−2α第2题Mechanicsofmaterialsisastudyoftherelationshipbetweenthe()appliedtoabodyandthe(

)and()causedbythe()withinthebody.Aloads,stress,strain,loadsBexternalloads,stress,strain,internalloadsCinternalloads,deformation,force,externalloadsDexternalloads,force,deformation,internalloads第3题Theinternalforceatacrosssectioncanusuallybesimplifiedas(

).AAprincipalvector;BAprincipalmoment;

CAprincipalvectorandaprincipalmoment;DAscalar.第4题Strength,stiffnessandstabilityofmembers(

).Aarerelatedtothemechanicalpropertiesofmaterials;Barerelatedtotheshapeandsizeofmembers;Carerelatedtothemechanicalpropertiesofmaterialsandtheshape,sizeofmembers;Darerelatedtoneitherthemechanicalpropertiesofmaterialsnortheshape,sizeofmembers.第5题Inthefollowingdiscussionabouttheinternalforceandstress,()iscorrect.ATheinternalforceisthealgebraicsummationofstress;BTheinternalforceisthevectorsummationofstress;CThestressistheaverageoftheinternalforce;DThestressistheintensityoftheinternalforce.Chapter7Assignment第1题Thebarshowninthefigureissubjectedtofourequalaxialexternalforces.Insegment(

)thedeformationiszero.A

ABBACCADDBC第2题Twobarswithdifferentcross-sections,oneiscircularandanotherisrectangular.Ifthetwobarshavethesamematerials,areasbutdifferentlengths,withthesameexternalforcesasshowninthefigure,forthetwobars()isdifferent.AaxialnormalstressσBaxialnormalstrainεCaxialelongationΔlDtransversestrainε’第3题Abariscomposedoftwomaterials,oneissteelwithEst=200GPaandanotherisbrasswithEbr=100GPa.Knowingthatthediameterofthebarisd=40mmandtheexternalloadF=20kN.TheelongationofthebarΔlis____mm.正确答案：:0.127第4题

Forthefollowingfourstatementsaboutσσr0.2,()iscorrect.A

σσr0.2isthestresscorrespondingtotheelasticstrainof0.2%;

Bσσr0.2isthestresscorrespondingtothetotalstrainof0.2%;Cσσr0.2isthestresscorrespondingtotheplasticstrainof0.2%;Dσσr0.2

isthestresscorrespondingtotheplasticstrainof0.2.第5题Theloweryieldpointistheminimumstressintheyieldstagewithoutconsideringtheinitialtransienteffect.Chapter8Assignment第1题Forthetwostressstates

aandb,____iscorrect.正确答案：:a第2题ThepinpassesthroughthecircularholeintheflatplateandissubjectedtoapullforceFatitslowerend.Theareasoftheshearplaneandbearingplaneofthepinarerespectively().A;B;C;D.第3题Therivetconnectionisshowninthefigure,andtheshearstressoftherivetis(

).A;B

;C;D.第4题Forconnectingmembers,theshearplaneandbearingplaneare(

).ARespectivelyperpendicularandparalleltothedirectionofexternalforces;BRespectivelyparallelandperpendiculartothedirectionofexternalforces;CBothparalleltothedirectionofexternalforces;DBothperpendiculartothedirectionofexternalforces.第5题TherelationofthethreeelasticconstantsE,G,μofisotropicmaterialsis().A

;B

;C

;D

.Chapter9Assignment第1题Thecircularshaftfixedattheleftendissubjectedtoseveralexternalcouples

asshowninthefigure,themaximumtorqueintheshaftis().A10kN·m

B5kN·mC15kN·mD20kN·m第2题

Ifthediameterofatorsionalsolidcircularshaftisdoubled,itsrigidityis8timesoftheoriginalone.第3题Forasolidcircularshaftandahollowcircularshaft,iftheyhavethesamematerial,cross-sectionalarea,lengthandaresubjectedtothesameexternaltorques,therearefouranswerstotherelationbetweenthetorsionalanglesofthetwoshafts,thecorrectoneis().A;B

;C;DCan'tcompare.第4题Asshowninthefigure,thecircularshaftismadeofsteelandcopperbywelding.IfitisactedbyanexternalcoupleMe,thecopperpartandthesteelpartarethesamein().AShearstressintorsion;BShearstrainintorsion;CAngleoftwist;DAngleoftwistperunitlength.第5题Thesolidcircularshaftwithlengthl,radiusrandtorsionalstiffnessGIPisshowninthefigure.Whentheshaftisintorsionthelongitudinallineonthesurfaceslantsanangleγ.Inthecaseofsmalldeformation,therearefouranswerstothetorqueTonthecross-sectionandtherelativetwistangleφwithrespecttobothends.Thecorrectansweris(

).A;B

;C

;D.Chapter10Assignment第1题Thecantileverbeamandthesimplysupportedbeamareequalinlength,theyhave().ADifferentbendingmomentdiagrambutthesameshearforcediagram;BThesamebendingmomentdiagrambutdifferentshearforcediagram;CThesamebendingmomentdiagramandthesameshearforcediagram;DDifferentbendingmomentdiagramanddifferentshearforcediagram.第2题Asshowninthefigure,thecantileverbeamissubjectedtoauniformlydistributedloadinthesegmentBC.Inthefollowingconclusions,()iswrong.ATheshearforceofeachcrosssectionisgreaterthanorequaltozero;BTheshearforceinsegmentABisconstant;CThebendingmomentofeachcrosssectionislessthanorequaltozero;DThebendingmomentinsegmentABisconstant.第3题Forplanebendingthecharacteristicofthedeformationis().AthecrosssectionremainsplanewhenbentBtheaxisafterdeformationisaplanecurveCallexternalloadsactonthesameplaneDtheaxisafterdeformationisinthesameplanewiththeloadingplane第4题IfthebendingmomentMinthebeamsegmentisalinearfunctionofx,thefunctionofshearforceis(

).Aconstant;B

linearfunction;Cquadraticfunction;D0.第5题Inthefollowingfigures,figure()showsthatthebendingmomentMonthesectionispositiveandtheshearforceFsisnegative.ABCDAppendixAAssignment第1题Inthegeometricpropertiesofplanes,thevaluesofstaticmomentandmomentofinertiacanbepositive,negativeandzero.第2题Fortheareaasshown,ifthecentroidalaxisZdividesthefigureintotwoparts,then()mustbeestablished.AIz1

=

Iz2;BA1

=

A2;CSz1

+

Sz2=0;DSz1

=

Sz2.第3题LetthemomentofinertiaoftherectangletoitssymmetricaxisZisI.Whentheratiooflengthtowidthremainsunchangedbuttheareaisdoubled,themomentofinertiaoftherectangletoitssymmetricaxisZwillbecome(

).A2IB4IC8ID16I第4题TheareaofthegraphisA,thex0axispassthroughthecentroidCandparalleltothex1axis,thedistancebetweenthex0axisandthex1axisisa.Itisknownthatthemomentofinertiaofthegraphwithrespecttox1axisisI1,andthemomentofinertiaofthegraphwithrespecttox0axisis().A;B

;C

;D

.第5题Ifthesectionareahasasymmetryaxis,thenfortheareatoitssymmetryaxis().ABoththestaticmomentandthemomentofinertiaarenotzero;BBoththestaticmomentandthemomentofinertiaarezero;CThestaticmomentisnotzero,themomentofinertiaiszero;DThestaticmomentiszero,themomentofinertiaisnotzero.Chapter11Assignment第1题Thecantileverbeamwithrectangularsectionisshowninthefigure.IfthemaximumnormalstressandthemaximumshearstressonsectionCareknowntobeσandτrespectively,thenormalstressσAattheupperandloweredgesofthefixedendandtheshearstressτA

ontheneutralaxisarerespectively().AσA＝σ

τA＝τ;BσA＝σ

τA＝2τ;CσA＝0

τA＝τ;DσA＝0

τA＝2τ.第2题Whenthebeamwithrectangularsectionisbent,intheneutralaxisofthecrosssection(

).AThenormalstressesaremaximum,theshearstressesarezero;BTheshearstressesaremaximum,thenormalstressesarezero;CBoththenormalstressesandshearstressesaremaximum;DBoththenormalstressesandshearstressesarezero.第3题ThecantileverbeamwithT-sectionsubjectedtheforceasshowninthefigure,whereZ0axispassesthroughthecentroidofthecrosssection,whichansweriscorrect?(

)ATheneutralaxisisZ0axis,andthemaximumtensilestressisattheupperedgeofthebeam;BTheneutralaxisisZ0

axis,andthemaximumtensilestressisattheloweredgeofthebeam;CTheneutralaxisisZ1axis,andthemaximumtensilestressisattheupperedgeofthebeam;DTheneutralaxisisZ1axis,andthemaximumtensilestressisattheloweredgeofthebeam.第4题Theforcesonthecantileverbeamareshowninthefigure,().APurebendingoccursinsegmentABandtransversebendingoccursinsegmentBC;BThebeamisinpurebendi