当前位置:考试网  > 试卷库  > 学历类  > 成考  > 高升专/本  >  如图所示,有n(n>6) 个相同的小物块(可视为质点)静止在倾角为θ的倾斜轨道上,物块与轨道间的动摩擦因数均为μ。每个物块的质量均为m ,相邻物块间的距离均为 l 。使第 1 个物块以某一初速度v0 沿轨道开始下滑, 在每次发生碰撞时物块都立即粘合在一起运动,且碰撞一直能持续下去,重力加速度为g。 (1)求第一次碰撞前瞬间小物块l的速度; (2)设第 5 次碰擅前的瞬间运动物块的动能为Ek5,第 5 次碰撞过程中系统损失的机械能为 E 损 5,求 E 损 5和 Ek5 的比值。
试题预览

如图所示,有n(n>6) 个相同的小物块(可视为质点)静止在倾角为θ的倾斜轨道上,物块与轨道间的动摩擦因数均为μ。每个物块的质量均为m ,相邻物块间的距离均为 l 。使第 1 个物块以某一初速度v0 沿轨道开始下滑, 在每次发生碰撞时物块都立即粘合在一起运动,且碰撞一直能持续下去,重力加速度为g。

1

(1)求第一次碰撞前瞬间小物块l的速度;

(2)设第 5 次碰擅前的瞬间运动物块的动能为Ek5,第 5 次碰撞过程中系统损失的机械能为 E 损 5,求 E 损 5和 Ek5 的比值。

查看答案
收藏
纠错
正确答案:

1

2

答案解析:

暂无解析

你可能感兴趣的试题

设 a,b,c 为实数,且 a>b, 则() 

下列地区中属于亚热带湿润地区的是( )

下列离子方程式书写正确的是()

我国东部地区降水的特点是 ( )

下列液体均处于25℃,有关叙述正确的是

热门试题 更多>
试题分类: 国家电网安规考试
练习次数:5次
PartIReadingComprehension Directions:Inthisparttherearefourpassages.Eachpassageisfollowedbyfourcomprehensionquestions.Readthepassageandanswerthequestions.ThenmarkyouranswerontheAnswerSheet. Passage1 Questions1to5arebasedonthefollowingpassage: Someyearsagothecaptainofashipwasveryinterestedinmedicine.Healwaystookmedicinebookstoseaandlikedtotalkaboutdifferentdiseases. Onedayalazysailoronhisshippretendedtobeill.Helayonhisbunk(铺)andgroanedasifhewereverysick.Thecaptaincametoseehimandwasverypleasedtohaveapatienttolookafter.Hetoldthemantorestforafewdaysandmadetheothersailorsdohiswork.Threedayslateranothersailorpretendedthathehadsomethingwrongwithhischest.Oncemorethecaptainlookedinhismedicalbooksandtold“sick”mantohavearest. Theothersailorswereveryangrybecausetheyhadmoreworktodo.Thepatientshadthebestfoodandlaughedattheirfriendswhenthecaptainwasnotlooking.Atlastthemate(船长副手)decidedtocurethe“sick”men.Hemixedupsomesoap,soot(烟灰),glue(胶水)andotherunpleasantthings.Thenheobtainedpermissionfromthecaptaintogivehismedicinetothe“sick”men.Whentheytastedthemedicine,theyreallydidfeelill.Itwassohorriblethatoneofthepatientsjumpedoutofhibunk,ranupondeskandclimbedthehighestmastontheship.Hedidnotwantanymoremedicine. Thematetoldbothofthementhattheymusttakethemedicineeveryhalfanhour,nightandday.Thissooncuredthem.Theybothsaidtheyfeltbetterandwantedtostartwordagain.Thecaptainrealizedthatthementriedtodeceivehimsohemadethemworkveryhardfortherestofthevoyage. 1.Thefirstsailorpretendedtobeillbecausehewantedto. A.testthecaptain’sknowledgeofmedicineB.befreefromwork C.havethebestfoodontheshipD.playajokeonhisfriends 2.Whenthecaptainknewasailorwasill,he. A.didn’tcaremuchB.sentforadoctor C.lookedafterhimandtoldhimtohavearestD.gavehimsomemedicine 3.Thepatientsfeltbetterquicklybecause. A.theyhadbeengivenpropermedicine B.theylearnedthatthecaptainhadfoundoutthetruth C.theywerelaughedatbytheirfriends D.themedicinethemategavewashorrible 4.Whenthecaptainknewhehadbeendeceived,he. A.toldthemnottodosoagainB.losthistemper C.madethemworkharderD.firedthem 5.Whichofthefollowingbestsummarizesthepassage? A.AsuddenCure.B.TwoPatients.C.CaptainandSailors.D.ADifficultVoyage.
试题分类: 大学英语四级
练习次数:1次
试题分类: 大学英语四级
练习次数:0次
PartIIICloze Directions:Therearetwentyblanksinthefollowingpassage.Foreachblanktherearefourchoices.ChoosetheonethatbestfitsintothepassageandthenmarksyouranswerontheAnswerSheet. In1982,MarkThatcher,thesonofMrs.Thatcherwasreported61intheSaharaDesertwhilecompetingintheGrandPrixmotorracefromParistoDakar.Thissadnews,so62,shooktheusuallycalmandunperturbedseasonedpolitician63herbalance.Thoughshedidherbesttopretendasif64hadhappenedandmadeherpublicappearancesasusual,peoplecouldnot65tonoticethatshewasnolongertheold66primeministerwhoalwayshadeverything67control.68shehadbecomeaverysadmotherwhowasunabletorecoverfromhershock. Oneday,whenshewastospeakataluncheonparty,areportercaughther69herguardby70upthesubjectofhermissingsonagain.Shewastotallymentally71forthequestionandlostherselfcontrol.Tearswererollingdownhereyesasshesobbinglytoldthereporterthatthere72stillnonewsofMarkandthatshewasveryworriedabouthim.Shesaidthatallthecountries73hadpromisedtodotheirbesttohelpherfindherson.74thatshebrokedowncompletelyandsobbedsilentlyforquiteawhile.Graduallyshe75downandstartedtospeakas76.itwasaverymovingscenewhich77anewsideofMrs.Thatcher’scharacterthepublicdonotusuallysee,78peoplebegantotalkabouttheIronWoman’smaternallove,asentimentthatis79toallhumankind. LaterMarkreturned80andsoundtohismother’sside,good-humoredandallsmilesasusual,asifnothingunusualhadeverhappened.TheIronWoman,however,brokedownagainaswassobbingforthesecondtime. 61.A.missingB.missedC.wantingD.wanted 62.A.expectedB.expectingC.unexpectedD.unexpecting 63.A.withB.onC.outD.off 64.A.somethingB.anythingC.nothingD.everything 65.A.missB.failC.pretendD.expect 66.A.reassuredB.self-assuredC.assuringD.self-assuring 67.A.forB.beneathC.belowD.under 68.A.InsteadB.howeverC.ThereforeD.So 69.A.intoB.outofC.onD.off 70.A.puttingB.bringingC.takingD.giving 71.A.readyB.preparedC.unpreparedD.unexpected 72.A.wasB.wereC.shouldbeD.wouldbe 73.A.concerningB.concernedC.worryingD.worried 74.A.AtB.BeforeC.AfterD.With 75.A.satB.brokeC.calmedD.became 76.A.plannedB.planningC.plansD.aplan 77.A.explainedB.exposedC.excludedD.exclaimed 78.A.howeverB.insteadC.soD.but 79.A.universalB.uniqueC.singleD.strange 80.A.safeB.safelyC.sightD.hearing
试题分类: 大学英语四级
练习次数:0次
Passage4 Questions16to20arebasedonthefollowingpassage: Cultureshockisanoccupationaldisease(职业病)forpeoplewhohavebeensuddenlytransplantedabroad. Cultureshockiscausedbytheanxietythatresultsfromlosingallfamiliarsignsandsymbolsofsocialintercourse.Thosesignsareasfollowing:whentoshakehandsandwhattosaywhenmeetpeople,whenandhowtogivetips,howtomakepurchases,whentoacceptandrefuseinvitations,whentotakestatementsseriouslyandwhennot.Thesesigns,whichmaybewords,gestures,facialexpressions,orcustoms,areacquiredbyallofusinthecourseofgrowingupandasmuchapartofourcultureasthelanguagewespeakorthebeliefsweaccept.Allofusdependonhundredsofthesesignsforourpeaceofmindandday-to-dayefficiency,butwedonotcarrymostatthelevelofconsciousawareness. Nowwhenanindividualentersastrangeculture,allormostofthesefamiliarsignsareremoved.Nomatterhowbroadmindedorfullofgoodwillyoumaybeaseriesofsupportshavebeenknockedfromunderyou,followedbyafeelingoffrustration.Whensufferingfromcultureshockpeoplefirstrejecttheenvironmentwhichcauseddiscomfort.Thewaysofthehostcountryarebadbecausetheymakeusfeelbad.Whenforeignersinastrangelandgettogetherincomplainaboutthehostcountryitspeople,youcanbesurethattheyaresufferingfromcultureshock. 16.Accordingtothepassage,cultureshockis. A.anoccupationaldiseaseofforeignpeopleB.mayleadtoveryserioussymptoms C.actuallynotadiseaseD.incurable 17.Accordingtothepassage,cultureshockresultfrom. A.thesuddenchangeofsocialatmosphereandcustoms B.thesuddenchangeofourdailyhabits C.thesuddenlossofourownsignsandsymbols D.thediscomfortthatwefeelwhenfacedwithaforeigner 18.Whichoneofthefollowingmaynotbeasymptomofcultureshock? A.Youdon’tknowhowtoexpressyourgratitude. B.Youdon’tknowhowtogreetotherpeople. C.Yousuddenlyforgetwhatawordmeans. D.Youdon’tunderstandwhyaforeignershrugs. 19.Accordingtothepassage,howwouldapersonwhostaysabroadmostprobablyreactwhenheisfrustratedbythecultureshock? A.Heismostlikelytorefusetoabsorbthestrangeenvironmentatfirst. B.Heisreallytoacceptthechangeandadapthimselftothenewenvironment. C.Althoughhetakestheculturedifferenceforgranted,hestilldoesn’tknowhowtodowithit. D.Hemaybegintohatethepeopleorthingsaroundhim. 20.Themainideaofthispassageisthat. A.cultureshockisanoccupationaldisease B.cultureshockiscausedbytheanxietyoflivinginastrangeculture C.cultureshockhaspeculiarsymptoms D.itisveryhardtocopewithlifeinanewsetting
试题分类: 大学英语六级
练习次数:1次
试题分类: 国家电网招聘考试
练习次数:1次
扫一扫,手机做题