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如图所示,两列简谐横波分别沿x轴正方向和负方向传播.已知两波源分别位于x=﹣0.2m和x=1.0m处,振幅均为A=0.5cm,波速均为v=0.2m/s.t=0时刻,平衡位置处于x=0.2m和x=0....
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如图甲为t=0时刻沿x轴方向传播的简谐横波图乙是横波上P.质点的振动图线则该横波
沿x轴正方向传播,波速为0.2m/s
沿x轴正方向传播,波速为20m/s
沿x轴负方向传播,波速为0.2m/s
沿x轴负方向传播,波速为20m/s
如图所示实线是沿x轴传播的一列简谐横波在t=0时刻的波形图虚线是这列波在t=0.2s时刻的波形图已知
这列波的波长是14cm
这列波的周期是0.125s
这列波可能是沿x轴正方向传播的
t = 0时,x = 4cm处的质点速度沿y轴负方向
周期为2.0s的简谐横波沿x轴传播该波在某时刻的图像如图所示此时质点P.沿y轴负方向运动则该波
沿 x 轴正方向传播,波速v = 20 m/s
沿 x 轴正方向传播,波速v =10 m/s
沿 x 轴负方向传播,波速v = 20m/s
沿 x 轴负方向传播,波速v =10 m/s
一列简谐横波在x轴上传播某时刻的波形如图所示.已知此时质点
的运动方向沿y轴负方向。则【 】A.波的传播方向为x轴负方向
质点
D.此时都向y轴负方向运动C.质点A.将比B.晚回到平衡位置
质点E.有最大的速度,且方向为y轴负方向
一列简谐横波在某时刻的波形如图所示此时质点M.向下运动则该波的振幅和传播方向分别为
)4cm,x轴正方向 (
)2cm,x轴正方向 (
)4cm,x轴负方向 (
)2cm,x轴负方向
如图所示两列简谐横波分别沿x轴正方向和负方向传播两波源分别位于x=-0.2m和x=1.2m处两列波的
=2cm.图示为t=0时刻两列波的图象(传播方向如图所示),此刻平衡位置处于x=0.2m和x=0.8m的P.、Q.两质点刚开始振动.质点M.的平衡位置处于x=0.5m处,关于各质点运动情况判断正确的是
A.t=1s时刻,质点M.的位移为-4cm
t=1s时刻,质点M.的位移为4cm
t=0.75s时刻,质点P.、Q.都运动到M.点
质 点P.、Q.的起振方向都沿y轴正方向
如图所示两列简谐横波分别沿x轴正方向和负方向传播两波源分别位于x=-0.2m和x=1.2m处两列波的
=2cm。图示为 t=0时刻两列波的图象(传播方向如图所示),该时刻平衡位置位于 x=0.2m 和 x=0.8m 的 P.、Q 两质点刚开始振动,质点 M 的平衡位置处于 x=0.5m 处。关于各质点运动情况的判断正确的是( )
A. t=0 时刻质点 P.、Q 均沿 y 轴正方向运动
t=1s 时刻,质点 M 的位移为-4cm
t=1s 时刻,质点 M 的位移为+4cm
t=0.75s 时刻,质点 P.、Q 都运动到 x=0.5m
周期为4s的简谐横波沿x轴传播该波在某时刻的图像如图所示此时质点P.正沿y轴正方向运动则该波
沿x轴正方向传播,波速v=5m/s
沿x轴负方向传播,波速v=5m/s
沿x轴正方向传播,波速v=10m/s
沿x轴负方向传播,波速v=10m/s
如图所示两列简谐横波均沿x轴传播传播速度的大小相等其中一列沿x轴正方向传播图中实线另一列沿x轴负方向
如图所示为一列沿x轴传播的简谐横波某时刻的图象已知从该时刻起图中质点a比质点b先回到平衡位置则下列说
波沿x轴正方向传播
此时刻质点b的速度方向沿y轴正方向
此时刻质点c的速度方向沿y轴正方向
此时刻质点d的加速度方向沿y轴正方向
如图所示两列简谐横波分别沿x轴正方向和负方向传播两波源分别位于x=-0.2m和x=1.2m处两列波的
=2cm.图示为t=0时刻两列波的图象(传播方向如图所示),此刻平衡位置处于x=0.2m和x=0.8m的P.、Q.两质点刚开始振动.质点M.的平衡位置处于x=0.5m处,关于各质点运动情况判断正确的是 A.t=1s时刻,质点M.的位移为-4cm
t=1s时刻,质点M.的位移为4cm
t=0.75s时刻,质点P.、Q.都运动到M.点
质 点P.、Q.的起振方向都沿y轴负方向
一简谐横波以4m/s的波速沿x轴正方向传播已知t=0时的波形如图所示则a点完成一次全振动的时间为sa
两列简谐横波分别沿x轴正方向和负方向传播两波源分别位于x=-0.2m和x=1.2m处波速均为v=0.
=2cm。图示为t=0时刻两列波的图象(传播方向如图所示),此刻平衡位置处于x=0.2m和x=0.8m的P.、Q.两质点刚开始振动。质点M.的平衡位置处于x=0.5m处,关于各质点运动情况判断正确的是 ( ) A.t=0.75s时,质点P.、Q.都运动到M.点
t=1s时,质点M.的位移为4cm
t=1s时,质点M.的位移为-4cm
质点P.、Q.的起振方向都沿y轴负方向
两列简谐横波的振幅都是20cm传播速度大小相同实线波的频率为2Hz沿x轴正方向传播虚线波沿x轴负方向
如图所示已知一列简谐横波沿x轴传播实线和虚线分别是方向与传播距离是
沿x轴正方向,6m
沿x轴负方向,6m
沿x轴正方向,2m
沿x轴负方向,2m
一列沿x轴正方向传播的简谐横波在xl=2m和x2=5m处的两质点的振动图象如图所示求①波的频率②波的
一列简谐横波沿x轴传播t=0时刻的波形如图甲所示此时质点P.正沿y轴负方向运动其振动图象如图乙所示则
沿x轴负方向,60 m/s
沿x轴正方向,60 m/s
沿x轴负方向,30 m/s
沿x轴正方向,30 m/s
如图所示实线是沿x轴传播的一列简谐横波在t=0时刻的波形图虚线是这列波在t=0.2s时刻的波形图已知
这列波的波长是14cm
这列波的周期是0.125s
这列波可能是沿x轴正方向传播的
t=0时,x=4cm处的质点速度沿y轴负方向
一列简谐横波沿x轴传播某时刻的波形如图所示已知此时质点F.的运动方向向y轴负方向则
)此波向x轴正方向传播 (
)质点
将比质点B.先回到平衡位置 (C.)质点C.此时向y轴负方向运动 (
)质点E.的振幅为零
一列简谐横波沿x轴传播t=0时刻的波形如图甲所示此时质点P.正沿y轴负方向运动其振动图象如图乙所示则
沿x轴负方向,60 m/s
沿x轴正方向,60 m/s
沿x轴负方向,30 m/s
沿x轴正方向,30 m/s
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已知abc分别为△ABC内角ABC的对边试从下列①②条件中任选一个作为已知条件并完成下列12两问的解答 ①= ②2ccosC=acosB+bcosA. 1求角C 2若c=a+b=求△ABC的面积.
若正四棱谁的所有棱长都相等则该棱锥的侧棱与底面所成的角的大小为.
8分Someofthebestresearchondailyexperienceisrootedinratesofpositiveandnegativeinteractionswhichhasprovedthatbeingblindlypositiveornegativecancauseotherstobefrustratedorannoyedoreventotuneout. Overthelasttwodecadesscientistshavemaderemarkablepredictionssimplybywatchingpeopleinteractwithoneanotherandthenscoringtheconversationsbasedontherateofpositiveandnegativeinteractions.Researchershaveusedthefindingstopredicteverythingfromthelikelihoodthatacouplewilldivorcetothechancesofaworkteamwithhighcustomersatisfactionandproductivitylevels. Morerecentresearchhelpsexplainwhythesebriefexchangesmattersomuch.Whenyouexperiencenegativeemotionsasaresultofcriticismorrejectionforexampleyourbodyproduceshigherlevelsofthestresshormonewhichshutsdownmuchofyourthinkingandactivatesconflictanddefensemechanisms机制.Yousupposethatsituationsareworsethantheyactuallyare. Whenyouexperienceapositiveinteractionitactivatesaverydifferentresponse.Positiveexchangesincreaseyourbody'sproductionofoxytocin后叶催产素afeel﹣goodthatincreasesyourabilitytocommunicatewithcooperatewithandtrustothers.Buttheeffectsofapositiveoccurrencearelessdramaticandlastingthantheyareforanegativeone. Weneedatleastthreetofivepositiveinteractionstooutweigheveryonenegativeexchange.Badmomentssimplyoutweighgoodones.Whetheryou'rehavingaconversationkeepthissimpleshortcutinmindAtleast80percentofyourconversationsshouldbefocusedonwhat'sgoingright. Workplacesforexampleoftenseethis.Duringperformancereviewsmanagersroutinelyspend80percentoftheirtimeonweaknessesandareasforimprovement.Theyspendroughly20percentofthetimeonstrengthsandpositiveaspects.Anytimeyouhavediscussionswithapersonorgroupspendthevastmajorityofthetimetalkingaboutwhatisworkingandusetheremainingtimetoaddressweaknesses. 1TheunderlinedphrasetuneoutinParagraph1probablymeans. A.gaincourage B.stoplistening C.singaloud D.feelstressed 2Whatwillhappenifyouexperiencenegativeemotions? A.Muchofyourthinkingwillbeprevented. B.Thesituationsaresuretobecomeworse. C.Youwillfeelanurgetoimproveandbecomebetter. D.You'llbemotivatedtoresolveconflictswithpeople. 3FromParagraph4wecanlearnthat. A.weneedapositivefeelingtobeatonenegativefeeling B.theeffectofnegativefeelingslastslongerthanthatofpositiveones C.ourconversationshouldcenteronwhatneedsimprovement D.positiveinteractionshavegreatereffectsthannegativeones 4Whatisthebesttitleforthepassage? A.HarmfulNegatives. B.LessTimeonStrengthsandPositiveAspects. C.HowtoBeaProductiveManager. D.MorePositiveInteractions.
两直角边分别为1的直角三角形绕其斜边所在的直线旋转一周得到的几何体的表面积是
△ABC中===在下列命题中是真命题的有
土笋冻是闽南种广受欢迎的特色传统风味小吃某小区超市销售一款土笋冻进价为每个15元售价为每个20元.销售的方案是当天进货当天销售未售出的全部由厂家以每个10元的价格回购处理.根据该小区以往的销售情况得到如图所示的频率分布直方图 1估算该小区土笋冻日需求量的平均数同一组中的数据用该组区间的中点值代表 2已知该超市某天购进了150个土笋冻假设当天的需求量为x个x∈N0≤x≤240销售利润为y元. i求关于x的函数关系式 ii结合上述频率分布直方图以额率估计概率的思想估计当天利润y不小于650元的概率.
15分MemorizinghundredsofEnglishwords1bealwaysabigheadacheforstudents.Whynotlet2amazingappBaicizhanhelpyou?Firstofalltheapphelpsyoudivideyourworkintodailytasks.3youhavechosenthevocabularylistandanenddatetheappthenquicklytellsyouhowmanywordsyouneedtolearneveryday.Forexampleyoucanspendjust10minutes4memorize15wordseveryday.Doesn'tthatsoundmuch5easythantryingtodoeverythingatonce?That'snotall﹣itcanalsobemuchfun.Thelearningprocessislikeplayingaguessinggame.Instead6justshowingtheChineseandEnglish7meaningofanewwordtheappasksyoutofirstchoosethecorrectpicturefromfour8baseonanEnglishdescription.Thishelpsyoumemorizethewords9clear.AndalloftheEnglishisreadbynativespeakers.Youcanalsolistento10itEnglishwordsradiofeaturewhileyou'rewalking.
2分Thethatitisdifficulttogetnewideasacceptedunlesstheyare.
15分BorninItalyGalileoGalileiwasaTuscanastronomerphilosopherandphysicist.Heiscloselyassociatedwiththe61sciencerevolution.Forhisgreat62achievementhehasbeenreferredtoasthefatherofmodemastronomy.TheworkofGalileo63considertobeasignificantbreakfromthatofAristotle.InadditionhisconflictwiththeRomanCatholicChurchistakenas64majorearlyexampleoftheconflictofauthorityandfreedomofthoughtparticularlywithscienceinWesternsociety.Hewasaman65experimented﹣neverdidhetakeanythingforgranted.Insteadhedespised蔑视theprejudicesandbooklearningoftheAristoteliansanddrewhisconclusion66fear.Hehadbeenthefirst67turnatelescopetotheskyandhehadseenthereevidenceenoughtooverthrowAristotleandPtolemytogether.AlthoughGalileofounditdifficulttomakepeople68convinceofhistheorieshestillstuck69hisviews.Hisobservationsshowedthetheorythattheearth70movearoundtheSunwasright.Itwasonlymanyyearslaterthattheworldrecognizedhisgreatness.
已知直三棱柱ABC﹣A1B1C1的所有顶点都在球0的表面上∠BAC=90°AA1=BC=2则•+=
已知mn是两条不同的直线αβ是两个不同的平面则下列命题中正确的是
2分Wehavefoundhumanandanimalbonesinthosecaveshigherupthehillaswellastoolsandotherobjects.Sowethinkitistheylivedinthesecaves.
8分Itwasoneofthehottestdaysofthedryseason.Wehadnotseenraininalmostamonth.Thecropsweredying.Cowshadstoppedgivingmilk.Thestreamswerelonggonebackintotheearth.Ifwedidn'tseesomerainsoonwewouldloseeverything. IwasinthekitchenmakinglunchformyhusbandandhisbrotherswhenIsawmysix﹣year﹣oldsonBillywalkingtowardthewoods.Hewasobviouslywalkingwithagreateffort…tryingtobeasstillaspossible.Minutesafterhedisappearedintothewoodshecamerunningoutagaintowardthehouse. Momentslaterhoweverhewasonceagainwalkinginthatslowpurposefullongsteptowardthewoods.Thisactivitywentonforoveranhourwalkingverycarefullytothewoodsthenrunningbacktothehouse.Finallymycuriositygotthebestofme.Iquietlywalkedoutofthehouseandfollowedhimonhisjourney. Hewascuppingbothhandsinfrontofhimashewalkedbeingverycarefulnottospill洒出thewaterheheldinthem.Branchesandthornsslappedhislittlefacebuthedidnottrytoavoidthem.Hehadamuchgreaterpurpose.AsIlookedathimsecretlyIsawthemostamazingsite. Severallargedeerappearedthreateninginfrontofhim.ButBillywalkedrightuptothem.Ialmostscreamedforhimtogetaway.AndIsawababydeerlyingonthegroundobviouslysufferingfromheavylossofwaterandheatexhaustionliftitsheadwithgreatefforttolapupthewatercuppedinmybeautifulboy'shand. IstoodontheedgeofthewoodswatchingthemostbeautifulheartIhaveeverknownworkingsohardtosavealife.Asthetearsthatrolleddownmyfacebegantohitthegroundtheyweresuddenlyjoinedbyotherdrops…andmoredrops…andmore.Ilookedupatthesky.ItwasasifGodhimselfwascryingwithpride. 21.Whydidtheauthorfollowherson? A.Becausetheremightbedanger. B.Becausehersonwasdoingagooddeed. C.Becauseshewascurious. D.Becausesheintendedtohelp. 22.WhichofthefollowingstatementsisNOTtrueaccordingtothepassage? A.Rainwasingreatneedatthetime. B.Billycarriedwaterwithhissmallhands. C.Therewerefewtreesinthewoods. D.Billywalkedintothewoodsmanytimes. 23.Whichisthecorrectorderofthedevelopmentofthestory? ①Theauthorwasmovedtotears. ②Billyfedthewatertothebabydeer. ③Billywalkedtowardsthelargedeer. ④Itbegantorain. ⑤TheauthorfollowedBillyintothewoods. A.⑤③②①④ B.③②⑤①④ C.④①③②⑤ D.⑤②①③④ 24.Whichofthefollowingisthebesttitleforthepassage? A.ImportanceofWater B.TheWaterofLife C.HowtoSaveAnimals D.AnimalsinDanger.
若z=3+4i则=.
10分 TheArtofSlowReading IfyouarereadingthisarticleinprintchancesarethatyouwillonlygetthroughhalfofwhatIhavewritten.Andifyouarereadingthisonlineyoumaynotevenfinishafifth.1Theysuggestthatmanyofusnolongerhavetheconcentrationtoreadarticlesthroughtotheirconclusion. Soarewegettingstupider?Actuallyouronlinehabitsaredamagingthementalpowerweneedtoprocessandunderstandtextualinformation.Round﹣the﹣clocknewsmakesusreadfromonearticletothenextwithoutnecessarilyengagingfullywithanyofthecontent.OurreadingisfrequentlystoppedbythenoiseofthelatestemailandwearenowabsorbingshortburstsofwordsonTwitterandFacebookmoreregularlythanlongertexts.2Butwearegraduallyforgettinghowtositbackthinkcarefullyandrelateallthefactstoeachother. 3Adesperatebunchofacademicswantustotakeourtimewhilereadingandre﹣reading.Theyaskustoswitchoffourcomputerseverysooftenandrediscoverboththejoyofpersonalengagementwithprintedtextsandtheabilitytoprocessthemfully.What'stobedonethen?Mostslowreadersrealizethattotalrejectionofthewebisextremelyunrealistic.Theyfeelthatgetawayfromtechnologyforawhileistheanswer.4 PersonallyI'mnotsurewhetherIcouldevergoofflineforlong.EvenwhilewritingthisarticleIamswitchingconstantlybetweensitesskimmingtoooftenabsorbingtoolittle.Internetreadinghasbecometoorootedinmydailylifeformetochange.IreadessaysandarticlesnotinhardcopybutasPDFs.Isuspectthatmanyreadersareinasimilarposition.5YoucandownloadacomputerapplicationcalledFreedomwhichallowsyoutoreadinpeacebycuttingoffyourInternetconnection.OrifyouwanttoavoidbeingdisturbedbytheInternetyoucouldalwaysdownloadofflinereaderInstapaperforyouriPhone.Ifyou'restillreadingmyarticlethatisslowreading. A.TheInternetisprobablypartoftheproblem. B.Nowsomecampaignsareadvocatingslowreading. C.Butifyoujustoccasionallywanttoreadmoreslowlyhelpisathand. D.Thesearethetwofindingsfromtherecentresearchprojects. E.BecauseoftheInternetwehavebecomeverygoodatcollectinginformation. F.Slowreadingcanhelpconnectareadertoneighborhoodandbecomepopular. G.Someofthemhavesuggestedturningtheircomputersoffforonedayaweek.
8分GrowingupinWyomingeverydaylifewasanadventure﹣Ispentmytimecampingandexploringmountains.WhenIwaslittlemymombecamethestate'sfirstfemaleU.S.Marshall.I'llneverforgethowthelocalnewspaperpraisedherforhersuccessinafieldthat'straditionallyrunbymen.UnderherinfluenceImadeupmymindtoachievesomethinggreat.NowI'vebecomefamousforsailingasportoftenconsideredaman'sworld. Sailingisconsideredahard﹣to﹣break﹣intosport.Andgenerallythereareonlytwowaystogetintoit﹣eitherthroughastrictsailingeducationthatleadstoexperienceorbygrowinguponthewaterandracingintheOlympics.MostofmyteammatesbecameprofessionalsailorsinoneofthesetwowaysbutIskippedboth. Inthesummerof2008IwenttoSt.Croixthroughacollegeinternship实习programfocusingoneducatinglocalsaboutHIVandAIDs.ThereIdiscoveredmyloveforsailing.ThenSCAaglobalhygiene卫生保健companymadethedecisiontosupportanall﹣femaleteamandwhentheybeganacceptingapplicationsIknewitwasthechanceofalifetime.Imadeitmytasktobecomeapartoftheteam.EvenwhenitseemedliketherewerenopositionsleftInevergaveup. Afterastressfultwo﹣yearapplicationprocessIfinallygotthecall.ImovedtoLanzaroteintheCanaryIslandsandbegantrainingwiththeteamimmediately.TheprocesswasphysicallymentallyandemotionallyexhaustingbutIfinallyachievedmygoal.IsailedintheEverestofsailingwithonlysixyears'experience.Latertherewasanall﹣femaleteamcompetingandIwasluckyenoughtobeapartofit. Aswomenweneedtoapproachourdreamsasifwedeservetoachievethemasmuchasmenbecausewedo.Thereareplentyofprofessionsincludingsailinginwhichwomenareabsentorhaveaminorpresence﹣butthat'snotbecausetheyshouldn'tbethere.Weneedtopushtheboundariesandfocusonobtainingourgoalsandpassionsnomatterhowunobtainableandchallengingtheymayseem. 1WhydoestheauthormentionhermotherinParagraph1? A.Tocomparewithhermother. B.Todescribewomen'sstruggles. C.Toanalyzehermother'ssuccess. D.Toshowhermother'sinfluenceonher. 2whatdoestheunderlinedwordbothinParagraph2probablyreferto? A.Twotraditionalwaystobecomeprofessionalsailors. B.Twoimportantpersonsintheauthor'slife. C.Twobasicstagesofbeingasailor. D.Twofamousprofessionalsailors. 3Whatisthecorrectorderofthefollowingevents? a.Ibegantrainingwiththesailingteam. b.Iattendedacollegeinternshipprogram. c.Itookpartincompetinginanall﹣femaleteam. d.Idiscoveredmyloveforsailingasawoman. A.b﹣d﹣a﹣c B.d﹣a﹣c﹣b C.a﹣c﹣d﹣b D.a﹣d﹣c﹣b 4Whichcanbestdescribetheauthor? A.Humorous. B.Generous. C.Pessimistic. D.Determined.
10分Identitytheftisarousingincreasingattentionfromthepublic.36Whenyouridentityisstolenthethiefoftendoesfraud诈骗withthat.Hemaygetacreditcardinyournameandspenditcarelesslywithoutpayingthebills.Hemaygetadriver'slicenseinyournameandyouwillbeheldresponsibleforthetrafficaccidentshecauses. WhyisidentitytheftbecomingSOcommon?37AndthewealthofprivatedetailspeoplepostonsocialnetworkssuchasFacebookalsomakesiteasierforidentitythievestoobtainprivateinformation. Manypeoplearenotawareoftheproblemscausedbythecrime.38 39ThisiswhyitisofimportancethateverypersonshouldbecomecautiouswhenusingtheInternet.Thefollowingtipsmaypreventyoufromidentitytheft. Firstmakesureyourcomputerhasanupdatedanti﹣virusandfirewallsysteminstalled.Second40Yourdateofbirthnamesofschoolsattendedphonenumberorthenamesofyourparentsareoftenrequiredtoverifyanidentityandthievescanusethisinformationtoo.Lastbutnotleastcreatecomplexpasswordsusingacombinationofnumbersandkeyboardsymbolsandchangeyourpasswordsonaregularbasis. A.AgatewayisofferedfortheidentitytheftbythepopularityoftheInternetandcomputers. B.Giveawayyourprivateinformationonsocialnetworkingsites谢也theutmostcaution. C.Thereisonesolutiontosolvetheproblem. D.Thisisacrimeinwhichyourprivateinformationisstolenbysomeoneandisusedinallillegalway. E.Theywakeupfromtheircarefreeattitudeonlywhentheybecomeavictimandsufferthedamagescausedbythecrime. F.Thereisnocureforidentitytheftexceptprevention. G.Theymayborrowmoneyfromthebankinyourname.
已知向量满足||=||=22﹣3⊥2+. 1求向量所成的角θ的大小 2若|+λ|=3求实数λ的值.
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