首页
试卷库
试题库
当前位置：
X题卡
>
所有题目
>
题目详情
如果ab+5＝12，则a与b成反比例． （判断对错）
查看本题答案
包含此试题的试卷
教案备课库《》真题及答案
点击查看
你可能感兴趣的试题
若7a=5b则ab成反比例．判断对错
如果AB=K+2K一定那么A和B成反比例．．判断对错
如果ab﹣5=15则a与b成反比例判断对错
如果y=那么x和y成反比例．．判断对错
a与b是两种相关联的量如果ab=1﹣ab那么a与b成反比例．．判断对错
如果AB=K+2K一定那么A和B成反比例．．判断对错
ab=1a与b成反比例．．判断对错
如果ab+5=12则a与b成反比例判断对错．
如果AB=KK一定那么A和B成反比例．判断对错
如果x与y成反比例那么3x与y也成反比例．．判断对错
如果y=8x那么x和y成反比例．判断对错
如果ab+5=15则a与b成反比例．．判断对错
如果ab+4=40那么a与b成反比例．判断对错
如果ab=10那么a和b成反比例．．判断对错
1.5分ab≠0如果ab+4=12则a与b成反比例．判断对错
如果y=5x那么x和y成反比例．判断对错
如果AB=K+πK一定那么A和B成反比例．．判断对错
如果xy-5=20那么x与y成反比例． ．判断对错
如果ab+5＝12则a与b成反比例．．判断对错
热门试题
更多
利用气垫导轨验证机械能守恒定律实验装置如图甲所示．水平桌面上固定一倾斜的气垫导轨导轨上有一装有长方形挡光片的滑块总质量为M滑块左端由跨过轻质光滑定滑轮的细绳和一质量为m的小球相连．导轨上的B点有一光电门可以测量挡光片经过光电门的时间t．实验时滑块由A处静止释放用L表示AB两点间的距离d表示挡光片的宽度． 1某次实验导轨的倾角为θ设重力加速度为g则滑块从A点到通过B点时m和M组成的系统的动能增加量△Ek＝系统的重力势能减少量△Ep＝在误差允许的范围内若△Ek＝△Ep则可认为系统的机械能守恒． 2设滑块经过B点的速度为v某同学通过改变AB间的距离L测得倾角θ＝37°时滑块的v2﹣L的关系如图乙所示并测得M＝0.5m则重力加速度g＝m/s2结果保留两位有效数字．
均匀分布在地球赤道平面上的三颗同步通信卫星能够实现除地球南北极等少数地区外的“全球通信”．已知地球半径为R地球表面的重力加速度为g同步卫星所在的轨道处的重力加速度为g′地球自转周期为T下面列出的是关于三颗卫星中任意两颗卫星间距离s的表达式其中正确的是 ①②③④⑤2R．
Fewjoysmatchthepleasureofreadingagoodbookandknowingthepeoplebehindit.Fromcomedytotragedywomenwritersfromthefourcornersoftheworldaregoingtotakethebookworldbystormthisyear.Herewemakeyoumeetfourofthebestwomenwritersof2017. LesleyNnekaArimah Arimahhasbecomeknownintheliteraryworldsinceshewasnamedafinalist参加决赛的选手fortheNationalMagazineAward.ThecollectionWhatItMeansWhenaManFallsfromtheSkyRiverheadfromwhichthenominated提名的shortstorywastakenwaspublishedinApril2017.Ithasbeennamedoneofthemostexpectedbooksof2017byTimemagazineTheChicagoTribuneTheBostonGlobeTheMillionsandTheMinneapolisStarTribune. JennyZhang Chinese﹣AmericanauthorZhang'sSourHeartacollectionofstoriesaboutagroupofteenagegirlsinNewYorkwillbepublishedbyLenaDunhamandJenniKonnerthissummer.KnownforherunexpectedwritingstyleZhanghasalreadymadehermarkinpoetrycircles. MaxineBenebaClarke AnothercomertotheliteraryballMaxineBenebaClarkeisanAustralianwriterwithAfro﹣Caribbeanorigins.InherhomecountryhernovelForeignSoilAtria/37INKhaswontheDebutFictionIndieAwardandtheLiteraryFictionBookoftheYear. SamantaSchweblin BorninArgentinaSchweblinisalreadyabignameintheSpanish﹣speakingworld.HergreatnovelFeverDreamRiverheadisherfirsttobetranslatedintoEnglishbyMeganMcDowellandissuretowintheheartsandmindsofmanyreaders 21.WhatdoweknowaboutLesleyNnekaArimah? A.Herwritingstyleissurprising. B.Shehashadseveralbookspublished. C.Shemadeanameinawritingcompetition. D.Herbookisthemostsuccessfulamongthefour. 22.WhosebookshouldyoureadifyouwanttolearnaboutAmericanyoungpeople? A.LesleyNnekaArimah's. B.JennyZhang's. C.MaxineBenebaClarke's. D.SamantaSchweblin's. 23.Whichofthefollowingisanaward﹣winningbookaccordingtothetext? A.WhatItMeansWhenaManFallsfromtheSky. B.SourHeart. C.ForeignSoil. D.FeverDream. 24.Whatcanweinferaboutthewomenwritersinthetext? A.Theysharethesamepublisher. B.TheyareEnglish﹣languagewriters. C.Theyjustbegintobeknownintheliteraryworld. D.Theytelloneormorestoriesintheirbooksintroduced.
如图所示为氢原子的能级图．用光子能量为13.06eV的光照射一群处于基态的氢原子可能观测到氢原子发射的不同波长的光有种其中最短波长为m已知普朗克常量h＝6.63×10﹣34J•s．
KendrickLamarhasn'thadmuchluckwhenitcomestowinningaGrammy.Butthat'sOKTheUSrapper说唱歌手hasjustwonaPulitzerPrizeforhismusic. In2014in2016andagainthisyear.Lamarwasnominated提名foranalbumoftheyearGrammy.EachtimehewasbeatenoutfirstbyTaylorSwiftnextbyDaftPunkandmostrecentlybyBrunoMars. ButthePulitzerPrizecommitteewasinspiredenoughbyLamar's2017albumDamntoawardthe30﹣year﹣olditsPulitzerPrizeinmusiconApril16.It'sanamazingalbumthatdocumentsthereallifeofmodemAfrican﹣AmericansinSouthLosAngeleswithwildlyaccomplishedbeatsandrhythms. Lamar'swinisconsideredtobehistorical.'ThePulitzershavelongdisplayedtheirpreferencetowardhighartratherthanthepopcultureofthemasses.Soit'snotjustthatnorapperhaseverwonaPulitzernopopmusicmakerhaseverwononeintheaward's75﹣yearhistory. ButLamarisnotjustasinger一he'scleveratusinglanguage.Likethebestwritershismusicdescribessmallmomentsthatillustrate阐明largerpoints.HissongsareAbouthisexperienceasablackmanwhogrewupinCaliforniastruggledgotintotroubleandfoundhiswayoutbyworkinghardandmakingsenseofthehistoryandrealityofracialproblemsintheUS. He'sanartistwhochallengesideasaidRyanCooglerdirectoroftheblockbuster大片hitBlackPantherforwhichLamarcreatedmusic.Onebigthemeinourfilmistheideaof'WhatdoesitmeantobeAfrican?'Kendrickinhismusicisveryexactlyanddirectlychallengingthatquestion. Goodartistsentertainusgreatartistsmakeusthinkandexceptionalartistshelpusempathize感同身受. Therearealotofgoodgreatevenexceptionalartistsinrockpopcountryandhip﹣hop.ButonlyLamarhasaPulitzerPrize. 1WhatisLamar'salbumDamnabout? A.African﹣Americans'historyandculture. B.HardshipsoftheAfrican﹣Americanartists. C.ThewaystheUSgovernmentdealwithracialproblems. D.ThelivesofmodernblackpeopleinSouthLosAngeles. 2WhyisLamar'sPulitzerPrizewinsignificant? A.Heisthefirstfilm﹣makertowintheprize. B.Itisconsideredamilestoneforpopmusic. C.Heisthefirstblackpersontowintheprize. D.HehasmissedGrammyseveraltimesbefore. 3WhatcanwelearnfromRyanCoogler'swords? A.Lamardrewinspirationfromhisownexperience. B.Lamarhasthecouragetotakeonbigchallengesinlife. C.BlackPantheriswellknownbecauseofLamar'smusic. D.Lamar'smusicmatchesthethemeofBlackPantherwell.
如图所示为密立根实验示意图两水平放置的金属板充电后与电源断开连接其板间距为d电势差为U现用一喷雾器把许多油滴从上板中间的小孔喷入板间若其中一质量为m的油滴恰好能悬浮在板间重力加速度为g则下列说法正确的是 A．该油滴所带电荷量为 B．密立根通过该实验发现了电子 C．该油滴所带电荷量可能为﹣2.0×10﹣18C D．若把上金属板向下平移一段距离该油滴将向上做加速运动
已知水的摩尔质量为18g/mol密度为1.0×103kg/m3阿伏伽德罗常数为6.0×1023mol试估算计算结果均保留一位有效数字． ①1200mL水所含的水分子数目 ②一个水分子的直径d
如图甲所示在光滑水平面上放置斜面体ABC水平部分AB与倾斜部分BC平滑连接ABBC表面均粗糙BC与水平面的夹角为θ＝37°．在斜面体右侧与竖直墙壁之间连接着一个力传感器规定力传感器受压时其示数为正值力传感器被拉时其示数为负值．一个质量m＝3kg可视为质点的滑块从斜面体的C点由静止开始下滑最终停在AB上某处．在整个运动过程中ABC始终保持静止力传感器测得的力F和时间t的关系如图乙所示．已知sin37°＝0.6cos37°＝0.8g取g＝10m/s2求 1滑块与AB的动摩擦因数μ1及滑块到达B点的速度vB 2在整个运动过程中滑块克服摩擦力做的功．
如图所示一由玻璃制成的直角三棱镜ABC其中AB＝AC该三棱镜对红光的折射率大于．一束平行于BC边的白光射到AB面上．光束先在AB面折射后射到BC面上接着又从AC面射出．下列说法正确的是
电影流浪地球正在热播观众分析流浪地球的发动机推动地球的原理行星发动机通过逐步改变地球绕太阳运行的行星轨道然后达到极限以后通过引力弹弓效应弹出地球整个流浪时间长达几十年．通过停止自转然后加大地球的反推力来逐步改变地球公转太阳轨道．具体过程如图所示轨道1为地球运行的近似圆轨道轨道23为椭圆轨道pQ为椭圆轨道长轴端点．以下说法正确的是
一根长度约为1米的空心铝管竖直放置把一枚小圆柱形永磁体从铝管上端管口放入管中．圆柱体直径略小于铝管的内径．永磁体在管内运动时不与铝管内壁发生摩擦且无翻转不计空气阻力．若永磁体下落过程中在铝管内产生的感应电动势大小与永磁体的磁性强弱和下落的速度成正比铝管的有效电阻恒定关于永磁体在铝管内运动的过程下列说法正确的是
Whydoesthegrassontheothersideofthefence篱笆alwayslookgreenerthanours?Whydoesitseemlikeothersaregettingmorebreaksandarehappierthanus?Haveyoueverfoundyourselfwonderingtheseexactthoughts?Wellyouarenotalone.It'sjusthumannatureforallofustothinklikethisoccasionally.Icallthisstinkingthinking. Fromtimetotimeweallfallintothetrapofstinkingthinking.We'reallinsecuresometimes.We'realljealousandmoodysometimes.Andthat'sjusthowlifeis.Thereisreallynotmuchwecandoaboutitexceptrealizethatthisnegativewayofthinkingexists.Byrealizingthatbadandnegativethoughtswilloccasionallyfinditswayintoourmindswecanbereadyforitwhenitdoesseepin渗入. Sowhenwe'rehavingoneofthosemomentsormaybeevenoneofthosedaysinwhichitseemslikeothershaveabetterlifethanuswefightitbynoticingournegativethoughtsandthensayingtoourselvesOhlook.Theregoesthatstinkingthinkingthingagain.Isn'titfunnyhowthatstinkingthinkingthingistryingtoruinmydayagain? Wellwe'renotgoingtoletitruinourdayarewe?Andwe'renotgoingtoletitbecauseweknowitexistsandwecanseewhatit'supto.We'renotgoingtoletthatstinkingthinkingorthatgreengrassontheothersidegettousanymore.We'regoingtorefusetobeavictimanymorebecauseweweren'tborntobevictims.Wewereborntobewinners!Fromnowonwewilltrainourbrainstoseeourowngreengrassandhaveourthoughtsworkforusinsteadofagainstus. 29.Whichofthefollowingisanexampleofstinkingthinking? A.Weshouldacceptourownfaults? B.Itishumannaturetoadmireothers. C.Weshouldenjoythegrassontheotherside. D.Itisalwaystheothermountainthatlookshigher. 30.Howcanwefightstinkingthinkingaccordingtotheauthor? A.Bydenyingitsexistence. B.Bylearningtofocusonourselves. C.Byignoringitsnegativeinfluence. D.Bystoppingcomparingwithothers. 31.Whatwouldbethebesttitleforthetext? A.Ourgrassisgreentoo B.Wewereborntobewinners C.Havepositivethoughtseveryday D.Thegrassontheothersideofthefence.
如图甲所示在粗糙的水平面上一质量m＝1kg可视为质点的滑块压缩一轻弹簧并被锁定滑块与弹簧不相连解除锁定前滑块处于P处t＝0时解除锁定计算机通过传感器描绘出滑块的速度时间图象如图乙所示其中oab段为曲线bc段为直线在t1＝1s时滑块已经在水平面上滑行x＝4m的距离．在滑块运动方向上与P相距7m的Q处有一竖直挡板若滑块与挡板碰撞被弹回时无能量损失g取10m/s2弹簧的劲度系数为0.8N/m则下列正确的是
假设你是李华上周你在超市因缺少五元钱无法结帐一个名叫Jack的交换生慷慨解囊帮你摆脱尴尬局面.请你根据以上信息给交流中心写一封信讲述此事并对Jack表示感谢. 注意1.词数100左右 2.可以适当增加细节以使行文连贯. .
在“测定金属的电阻率”实验中所用测量仪器均已校准．待测金属丝接入电路部分的长度约为50cm． 1用螺旋测微器测量金属丝的直径其中某一次测量结果如图1所示其读数应为mm该值接近多次测量的平均值． 2用伏安法测金属丝的电阻Rx．实验所用器材为电池组电动势3V内阻约1Ω电流表内阻约0.1Ω电压表内阻约3kΩ滑动变阻器R0～20Ω额定电流2A开关导线若干．某小组同学利用以上器材正确连接好电路进行实验测量记录数据如下 由以上实验数据可知他们测量Rx是采用图2中的图选填“甲”或“乙”． 3图3是测量Rx的实验器材实物图图中已连接了部分导线滑动变阻器的滑片P置于变阻器的一端．请根据2所选的电路图补充完成下图中实物间的连线． 4这个小组的同学在坐标纸上建立UI坐标系如图4所示图中已标出了与测量数据对应的4个坐标点．请在图中标出第357次测量数据的坐标点并描绘出UI图线．由图线得到金属丝的阻值Rx＝Ω保留两位有效数字． 5根据以上数据可以估算出金属丝电阻率约为填选项前的符号． A．1×10﹣2Ω•mB．1×10﹣3Ω•m C．1×10﹣6Ω•mD．1×10﹣8Ω•m．
如图所示x轴的上方存在方向与x轴成θ＝45o．角的斜向下的匀强电场电场强度为Ex轴的下方存在垂直纸面向里的匀强磁场磁感应强度大小B＝0.5T．有一个质量m＝l×10﹣11kg电荷量q＝l×10﹣7C的带正电粒子该粒子从P点由静止释放后经M点进入匀强磁场又从N点返回电场经电场作用后第二次仍从M点进入磁场已知MN两点间的距离为x＝0.2m设电场和磁场的区域足够足够宽不计粒子重力求 1带电粒子第一次进人磁场时的速度大小v0 2电场强度E的大小 3带电粒子从P点出发到第二次到达M点所用的时间t．
下列四幅图分别对应四种说法其中正确的是
用如图甲所示的装置来验证碰撞过程中的动量守恒．图中PQ是斜槽QR为水平槽．O点是水平槽末端R在记录纸上的垂直投影点AB两球的质量之比mAmB＝31．先使A球从斜槽上固定位置G由静止释放在水平地面的记录纸上留下落点痕迹重复10次得到10个落点．再把B球放在水平槽上的末端R处让A球仍从位置G由静止释放与B球碰撞碰后AB球分别在记录纸上留下各自的落点痕迹重复10次．AB两球在记录纸上留下的落点痕迹如图乙所示其中米尺的零点与O点对齐． 1碰撞后A球的水平射程应取cm． 2本实验巧妙地利用小球飞行的水平距离表示小球的水平速度．下面的实验条件中不能使小球飞行的水平距离表示为水平速度的是． A．使AB两小球的质量之比改变为51 B．升高固定点G的位置 C．使AB两小球的直径之比改变为13 D．升高桌面的高度即升高R点距地面的高度 3利用此次实验中测得的数据计算碰撞前的总动量与碰撞后的总动量的比值为．结果保留三位有效数字
某住宅区的应急供电系统由交流发电机和副线圈匝数可调的理想降压变压器组成．发电机中矩形线圈所围成的面积为S匝数为N电阻不计它可绕水平轴OO′在磁感应强度为B的水平匀强磁场中以角速度ω匀速转动．矩形线圈通过滑环连接降压变压器滑动触头P上下移动时可改变输出电压R0表示输电线的电阻以线圈平面与磁场平行时为计时起点下列判断正确的是
如图甲所示的陀螺可在圆轨道的外侧旋转而不脱落好像轨道对它施加了魔法一样被称为“魔力陀螺”该玩具深受孩子们的喜爱．其物理原理可等效为如图乙所示的模型半径为R的磁性圆轨道竖直固定质量为m的小铁球视为质点在轨道外侧转动AB两点分别为轨道上的最高最低点．铁球受轨道的磁性引力始终指向圆心且大小不变不计摩擦和空气阻力重力加速度为g．下列说法正确的是
如图所示在倾角为θ的斜面上放置一内壁光滑的凹槽A凹槽A与斜面间的动摩擦因数μ＝槽内紧靠右挡板处有一小物块B它与凹槽左挡板的距离为d．AB的质量均为m斜面足够长．现同时由静止释放AB此后B与A挡板每次发生碰撞均交换速度碰撞时间都极短．已知重力加速度为g．求 1物块B从开始释放到与凹槽A发生第一次碰撞所经过的时间t1． 2B与A发生第一次碰撞后A下滑时的加速度大小aA和发生第二次碰撞前瞬间物块B的速度大小v2． 3凹槽A沿斜面下滑的总位移大小x．
WhenshefirststartedlearningabouttheclimatechangefromoneofhereldersFawnSharpwasinvitedonahelicopterflightovertheOlympicMountainstosurveytheMountAndersonglacier冰川.Buttheglacierwasgonemeltedbythewarmingclimate.Sharphadadeepsenseoflosswhenshediscoveredtheglacierwasn'tthereanymore. Lossisagrowingissueforpeopleworkingandlivingonthefrontlinesofclimatechange.AndthatgaveJenniferWrenAtkinsonafull﹣timelecturerattheUniversityofWashingtonBothellUSanideaforaclass. ThistermshetaughtstudentsontheBothellcampusabouttheemotionalburdensofenvironmentalstudy.SheusedtheexperiencesofNaliveAmericantribes部落scientistsandactivistsandaskedher24studentstofacetherealitythatthereisnoeasyfix﹣﹣thatthisissuchanintractableproblemthatthey'regoingtobedealingwithitfortherestoftheirlives. StudentCodyDillonusedtobeaclimatescienceskeptic怀疑论者.Thenhedidhisownreadingandresearchandchangedhismind. Dillonwasn'tgoingintoenvironmentalwork﹣﹣hewasacomputer﹣sciencemajor.Yetthepotentialforaworldwideenvironmentalcatastropheseemedsorealtohimfiveyearsagothathequithisjobandbecameafull﹣timevolunteerforanenvironmentalgroupthatworkedonrestoration恢复projects. SixmonthsintotheworkhedecidedthatAlkinson'sclasswasjustwhathewaslookingfor﹣﹣aplacewherehecoulddiscusshisconcernsaboutachangingclimate. Atkinsonsaidshehopestheclasshelpedherstudentspreparethemselvesfortheamountofenvironmentallossthatwillhappenovertheirlifetimes. Wearealreadychangingtheplanet﹣.somanyspeciesaregoingtobelostdisplacedormassivelyimpacted巨大影响的shesaid.Thefutureisn'tgoingtobewhattheyimagined. 1WhydidtheauthormentionthecaseofFawnSharp? A.TolayabasisforFawnSharp'sfurtherresearch. B.ToproveFawnSharp'sworkissimilartoAtkinson's. C.Toleadintotheissueoflosscausedbyclimatechange. D.Toshowscientists'concernabouttheMountAndersonglacier. 2What'sthemainpurposeofAtkinson'sclass? A.Toexplorehowdifferentpeopledealwithclimatechange. B.Togetstudentsmoreconcernedaboutenvironmentalissue. C.TofindsolutionstotheOlympicMountainsenvironmentalissue. D.Toteachstudentshowtoconductaresearchaboutenvironment. 3WhichofthefollowingbestexplainsintractableunderlinedinParagraphThree? A.Simple. B.Difficult. C.Common. D.Interesting. 4HowdidAtkinson'sclassinfluenceDillon? A.Dillonworkedasapart﹣timevolunteerforrestorationprojects. B.Itmadehimrealizeaplanet﹣wideclimatedisasterwouldhappen. C.Itencouragedhimtobemoreinvolvedinenvironmentalprotection. D.Itdiscouragedhimtoworkonrestorationprojectsfortheenvironment.
TheInternethasvariouspositiveeffectsonourlives.FirsttheInternetisagoodsourceforpeopletolookforinformation.Whetheryouwanttoreadnewslearnabouttheweather61findtravelpackagesyoucanfindalltheinformationyouwantontheInternet.AlsotheInternetisagoodtoolforpeople62buildsocialbonds.FriendshipsthatareformedontheInternetmaylastalifetime.BesidestheInternetisagoodavenueforthe63disabletocommunicatewithothersaroundtheworld. HowevertheInternetalsohasnegativeeffectsonourlives.ThoughitisagoodsourceofinformationnotallinformationontheInternet64betrueoraccurate.Asaresultstudentsmayfindthefalseinformationwhen65preparetheirpapers.Buttheseproblemscanbeavoidediftheyuse66traditionreferencematerials.Another67advantageoftheInternetis68itaffectspeople'sprivatelives.NowfamiliesarenotascloseasbeforebecausesomefamilymembersusetheInternettoomuch.AlsotheInternetusedamagespeople'sabilitytolivenormallivesiftheusersareaddicted69it. WeshouldmakegooduseoftheInternetandtryourbesttoavoid70itnegativeeffects.
Everyoneofusishighlyimportanteachofushassomethingofgreatvaluetooffertheworldandeverybodyisuniquelydifferentandskilledindifferentways.You'veprobablyreadsuchstatementsbefore.36Howeversometimesit'sveryhardtofeelthatwayandtobelievethatyougenuinelyhavethesameamounttoofferaseveryoneelse.Ifthatdescribesyouthenyoumayjusthaveaninferioritycomplex自卑感whichcanaffecteverysingleaspectofyourlife. 37Butittendstobetheresultofsignificanteventsorofconditionedbeliefsthatcomefromcontinuousfailureorcriticism批评.Oftenparentalattitudescanresultinaninferioritycomplex.38Insomecasesaninferioritycomplexcouldalsoariseasaresultofsomekindsoffaultseitherphysicalormental. Fortunatelytherearemanythingsyoucandotoovercomeaninferioritycomplex.Forexamplewhenyoutalktosomeonethinkaboutwhentheystutter结巴orwhethertheyhaveagoodvocabulary.39Butifyoudofocusonthemthenyou'llbeabletonotehowunlikelytheyaretobejudgingyou.Ifyou'reupsetwithyourlackofconfidencedon'tworrybecauseyoucantakeactiontomakeyourselfbecomewhatyouwanttobe.40Forexampleyoumightchooseasportorwoodworkandthenyoucanpracticegettingbetteratthatandgainmoreconfidencefromthatarea. A.Youcanalsotakeupahobby. B.It'sunkindtothinkthesethings. C.Therearemanypossiblecausesofinferiority. D.Thiswillshowyouhowlittlepeoplecareaboutyou. E.Andalsoyoumightagreewiththemonalogicalandconsciouslevel. F.Theyviewthemselvesasgenerallylessimportantsuccessfuloraccomplished. G.Forexampleachildwhoisoftenignoredathomeismorelikelytofeelinferior.
下列说法中正确的是
物理学是一门实验学科是以实验为基础的．在物理学的发展过程中许多重要的物理规律都是由实验发现或由实验验证了的下列有关物理实验中涉及的思想或方法说法正确的是 A．a图为探究影响电荷间相互作用力的因素的实验图该实验利用了等效替代的思想 B．b图库伦的扭秤实验装置图该实验利用了微小量放大法的思想 C．c图为伽利略研究落体运动的规律在该实验中伽利略通过减小斜面的倾角直接验证了物体下落的速度与时间成正比 D．d图为探究求合力的方法的实验装置图该实验利用了控制变量的思想
图1是某种电动势不变而内阻随电流的变化而变化的电源的U﹣I图线图2是一滑块从某一斜面滑下的过程中机械能随滑动距离而变化的图线斜面上各处动摩擦因数不同关于这两条图线下列说法正确的是
下列说法正确的是
abc三条平行光线从空气射向玻璃砖且方向垂直于半圆柱体玻璃砖的截面直径如图所示光线b正好过圆心O光线ac从光线b的两侧对称入射光线ac从玻璃砖下表面进入空气后与光线b交于PQ则下列说法正确的是
“新视野号”探测器在北京时间2015年7月14日1945飞掠冥王星若“新视野号”由椭圆轨道变轨进入更低的冥王星圆轨道已知制动点为椭圆轨道和圆轨道的切点万有引力常量G＝6.67×10﹣11N•m2/kg2则以下分析正确的是
热门题库
更多
教案备课库
教案备课库
教案备课库
教案备课库
教案备课库
教案备课库
教案备课库
教案备课库
教案备课库
高一上学期英语
高一下学期化学
高一下学期物理
高三下学期数学
高三上学期数学
高一下学期英语
教案备课库
湘公网安备 43130202000226号