【MOOC】Engineering Mechanics-Northwestern Polytechnical University 中國大學(xué)慕課MOOC答案

【MOOC】EngineeringMechanics-NorthwesternPolytechnicalUniversity中國大學(xué)慕課MOOC答案Ch1Freebodydiagram1、【單選題】本題答案：【b】2、【單選題】本題答案：【C】3、【單選題】本題答案：【D】4、【單選題】本題答案：【C】5、【單選題】本題答案：【D】6、【單選題】本題答案：【D】7、【單選題】本題答案：【B】Ch2FundmentalForcesystem1、【單選題】本題答案：【C】2、【單選題】本題答案：【B】3、【單選題】本題答案：【D】4、【單選題】本題答案：【A】5、【單選題】本題答案：【C】6、【單選題】本題答案：【B】7、【單選題】本題答案：【C】8、【單選題】本題答案：【D】9、【單選題】本題答案：【D】10、【單選題】本題答案：【A】11、【多選題】本題答案：【C#D】12、【多選題】本題答案：【A#D】Ch3:GeneralCoplanarForceSystem1、【單選題】本題答案：【C】2、【單選題】本題答案：【D】3、【單選題】本題答案：【AforcepassingbypointO】4、【單選題】本題答案：【Aforcecouple】5、【單選題】本題答案：【D】6、【單選題】本題答案：【FBC=245.24N】7、【單選題】本題答案：【A】8、【單選題】本題答案：【B】9、【單選題】本題答案：【C】10、【單選題】本題答案：【A】11、【單選題】本題答案：【A】12、【單選題】本題答案：【D】13、【多選題】本題答案：【884.5N#FAx=736N,FAy=490.5N】Ch4EquilibriumofaBodySystem1、【單選題】本題答案：【C】2、【單選題】本題答案：【250N】3、【單選題】本題答案：【A】4、【單選題】本題答案：【B】5、【單選題】本題答案：【B】6、【單選題】本題答案：【15kN】7、【單選題】本題答案：【40kN】8、【單選題】本題答案：【Fcx=F，F(xiàn)cy=F】9、【單選題】本題答案：【MA＝12kN·m】Ch5Friction1、【單選題】本題答案：【Keepstatic.】2、【單選題】本題答案：【Sliding.】3、【單選題】本題答案：【Aissliding.Bkeepstatic.】4、【單選題】本題答案：【Keepstatic.】Chapter6IntroductiontoMechanicsofMaterials1、【單選題】Strength,stiffnessandstabilityofmembers().本題答案：【Relatedtothemechanicalpropertiesofmaterialsandtheshape,sizeofmembers.】2、【單選題】Inthefollowingdiscussionabouttheinternalforceandstress,()iscorrect.本題答案：【Thestressistheintensityoftheinternalforce.】3、【單選題】Whenwestudytheequilibriumofamemberorapartofit,wecanusetheoriginalsizesbeforedeformationtoanalyze,thatbecauseweadoptthe().本題答案：【Limitationofsmalldeformation;】4、【單選題】Theinternalforceonacrosssectioncanusuallybesimplifiedas().本題答案：【Aprincipalvectorandaprincipalmoment;】5、【單選題】Inthefollowingconclusions,()iswrong.本題答案：【Iftheobjectdisplaces,itmustdeformatthesametime.】Chapter7AxialTensionandCompression1、【單選題】Asshowninthefigure,twodeformationmeasuringinstrumentsarerespectivelyinstalledatAandBofthetensiletestspecimen,themagnificationisrespectivelyand.Thegaugelengthiss=20mm,andthereadingincrementofthemeasuringinstrumentaftertensionis,.ThenthePoisson'sratioμofthismaterialis().本題答案：【1/3;】2、【單選題】Forthesimplecraneshowninthefigure,BCisasteelbarandABisawoodbar.Thecross-sectionalareaofABis,allowablenormalstress;thecross-sectionalareaofBCisAst=6cm2,allowablenormalstress.ThentheallowableliftingweightFis().本題答案：【40.5kN;】3、【單選題】Therearethreeconcentratedforcesareappliedatthebar,asshowninthefigure.Theaxialforceonsectionm-mis().本題答案：【.】4、【單選題】Asteppedbarisshowninthefigure,segmentABismadeofsteelandsegmentBDismadeofaluminum.WiththeexternalforcesF,().本題答案：【forthethreesegmentstheyhavethesameaxialforce.】5、【單選題】Twobarswithdifferentcross-sections,oneiscircularandanotherisrectangular.Ifthetwobarshavethesamematerials,areasbutdifferentlengths,withthesameexternalforcesasshowninthefigure,forthetwobars()aredifferent.本題答案：【axialnormalstressσ;】6、【單選題】Thebarshowninthefigureissubjectedtofourequalaxialexternalforces.Insegment()thedeformationiszero.本題答案：【BC.】Chapter8Shear1、【單選題】ThepinpassesthroughthecircularholeontheflatplateandissubjectedtoapullforceFatitslowerend.Theareasoftheshearplaneandbearingplaneofthepinarerespectively().本題答案：【本題答案：【本題答案：【Respectivelyparallelandperpendiculartothedirectionofexternalforces】4、【單選題】Therivetconnectionisshowninthefigure,andthebearingstressoftherivetis().本題答案：【本題答案：【aiscorrect;】Chapter9Torsion1、【單選題】Ahollowcircularshaftwiththeratioofinnerandouterdiametersα=d/D,ifthemaximumshearstressonthecrosssectionisτwhenthetwoendsaresubjectedtothetorsionalcouplemoments,thentherearefouranswerstotheshearstressattheinnercircumference,thecorrectoneis().本題答案：【;】2、【單選題】Theprismatictransmissionshaftisshowninthefigure.WheelsBandDaredrivingwheelsandwheelsA,C,Earedrivenwheels.IftheinputpowersondrivingwheelsBandDareequal,theoutputpowersondrivenwheelsA,CandEareequaltoo,andifonlytorsionaldeformationisconsideredandbendingdeformationisnotconsidered,thepositionofdangeroussectionis().本題答案：【InsegmentABandsegmentDE.】3、【單選題】Asshowninthefigure,thecircularshaftismadeofsteelandcopperbywelding.Ifitisactedbyanexternalcouple,thecopperpartandthesteelpartarethesamein().本題答案：【Shearstressintorsion;】4、【單選題】Forasolidcircularshaftandahollowcircularshaft,iftheyhavethesamematerial,cross-sectionalarea,lengthandaresubjectedtothesameexternaltorques,therearefouranswerstotherelationbetweenthetorsionalanglesofthetwoshafts,thecorrectoneis().本題答案：【】5、【判斷題】Ifthediameterofthetorsionalsolidcircularshaftisdoubled,itsrigidityis8timesoftheoriginalone.本題答案：【錯誤】Chapter10InternalForcesinBending1、【單選題】Inthefollowingfigures,figure()showsthatthebendingmomentMonthesectionispositiveandtheshearforceisnegative.本題答案：【】2、【單選題】IfthebendingmomentMonthebeamsegmentisalinearfunctionofx,thefunctionofshearforceis().本題答案：【Constant;】3、【單選題】Forplanebendingthecharacteristicsofdeformationare().本題答案：【Theaxisafterdeformationisinthesameplanewiththeloadingplane.】4、【單選題】Asshowninthefigure,thecantileverbeamissubjectedtoauniformlydistributedload.Inthefollowingconclusions,()iswrong.本題答案：【ThebendingmomentinsegmentABisconstant.】5、【單選題】Thecantileverbeamandthesimplysupportedbeamareequalinlength,theyhave().本題答案：【Thesamebendingmomentdiagramsandthesameshearforcediagrams;】AppendixAMomentsofAreas1、【單選題】Ifthesectionfigurehasasymmetryaxis,thenforthefigure()toitssymmetryaxis.本題答案：【Thestaticmomentofinertiaiszero,themomentofinertiaisnotzero.】2、【單選題】TheareaofthegraphisA,theaxispassthroughthecentroidCandparalleltotheaxis,thedistancebetweenaxisandtheaxisis.Itisknownthatthemomentofinertiaofthegraphwithrespecttoaxisis,andthemomentofinertiaofthegraphwithrespecttoaxisis().本題答案：【本題答案：【4I;】4、【單選題】Forthefigureasshown,ifthecentroidalaxisZdividesthefigureintotwoparts,then()mustbeestablished.本題答案：【】5、【判斷題】Inthegeometricpropertiesofplanes,thevaluesofstaticmomentofinertiaandmomentofinertiacanbepositive,negativeandzero.本題答案：【錯誤】Chapter11StressesinBending1、【單選題】Inthefollowingcases,()belongstopurebending.本題答案：【Thereisnoshearforceoneachcrosssectionofthemember,andthebendingmomentisaconstant.】2、【單選題】Theforcesonthecantileverbeamareshowninthefigure,().本題答案：【PurebendingoccursinsegmentABandtransversebendingoccursinsegmentBC;】3、【單選題】ThecantileverbeamwithT-sectionsubjectedtheforceasshowninthefigure,whereaxispassesthroughthecentroidofthecrosssection,whichis()ofthecrosssectionofthebeam.本題答案：【Theneutralaxisisaxis,andthemaximumtensilestressisattheloweredgeofthebeam;】4、【單選題】Whenthebeamwithrectangularsectionisbent,intheneutralaxisofthecrosssection().本題答案：【Shearstressesaremaximum,normalstressesarezero;】5、【單選題】Asshowninthefigure,thecantileverbeamwithconstantsectionissubjectedtoaconcentratedforceandaconcentratedcouple.IfthemaximumnormalstressandthemaximumshearstressatcrosssectionCareσandτrespectively,themaximumnormalstressandthemaximumshearstressatcrosssectionAare().本題答案：【0andτ.】Chapter12DeflectionofBeams1、【單選題】Fortwobeamswithsamelength,flexurerigidityEIandbendinginternalforcediagrams,inthesamecoordinatesystemthebeams().本題答案：【Havedifferentdeflectionequationsbutsamecurvatureequations;】2、【單選題】Thecantileverbeamissubjectedtoexternalforcesasshowninthefigure,oncrosssectionB().本題答案：【Boththedeflectionandtheangleofrotationarezero.】3、【單選題】Fortwocantileverbeamswithsamelength,loadingform,flexuralrigidityEIbutdifferentcross-section,theyhave().本題答案：【Differentmaximumnormalstressbutsamemaximumdeflection;】4、【單選題】Fortheapproximatedifferentialequationofthedeflectioncurve本題答案：【W(wǎng)ith本題答案：【Meettheaboveconditionsatthesametime.】2021.6FInalExam1、【單選題】本題答案：【FAx=2100N，F(xiàn)Ay=1000N】2、【單選題】本題答案：【σ1＞σ2＞σ3】3、【單選題】本題答案：【τS＞τA】4、【單選題】本題答案：【σA＝0τA＝τ】5、【單選題】ThecompoundbeamispinconnectedatBasshowninFigure.Determinethereactio