首页
试卷库
试题库
当前位置:
X题卡
>
所有题目
>
题目详情
已知函数f(x)=|x+2|. (1)求不等式f(x)+f(x﹣2)<x+4的解集; (2)若∀x∈R,使得f(x+a)+f(x)≥f(2a)恒成立,求a的取值范围.
查看本题答案
包含此试题的试卷
高三下学期数学《》真题及答案
点击查看
你可能感兴趣的试题
选修4—5不等式选讲 已知函数fx=∣2x-a∣+a I当a=2时求不等式fx≤6的解集 II设函
已知函数fx=|2x-a|+a I当a=2时求不等式fx≤6的解集 II设函数gx=|2x-1|当
已知函数fx=–x2+ax+4gx=│x+1│+│x–1│.1当a=1时求不等式fx≥gx的解集2若
已知函数fx=|x+m|+|2x﹣1|m∈R..1当m=﹣1时求不等式fx≤2的解集2设关于x的不等
选修4-5不等式选讲已知函数fx=|x+a|.Ⅰ当a=-1时求不等式fx≥|x+1|+1的解集Ⅱ若不
已知函数fx=|x-a|其中a>1.1当a=2时求不等式fx≥4-|x-4|的解集2已知关于x的不等
已知a∈R.函数fx=x2+2a+1xgx=ax.1解关于x的不等式fx≤gx2若不等式|fx|≥g
选修4—5不等式选讲 已知函数fx=∣x+1∣-∣2x-3∣ I画出y=fx的图像 II求不等式∣
已知函数fx=|x|+|x﹣2|.1求关于x的不等式fx<3的解集2如果关于x的不等式fx<a的解集
已知函数fx=|x﹣2|1解不等式xfx+3>02对于任意的x∈﹣33不等式fx<m﹣|x|恒成立求
已知函数fx=|x﹣a|其中a>11当a=2时求不等式fx≥4﹣|x﹣4|的解集2已知关于x的不等式
选修4-5不等式选讲已知函数fx=log2|x+1|+|x-2|-m.I.当m=7时求函数fx的定义
选修4-5不等式选讲已知函数fx=log2|x+1|+|x-2|-m.I.当m=7时求函数fx的定义
已知函数fx=|x-a|其中a>1.1当a=2时求不等式fx≥4-|x-4|的解集;2已知关于x的不
已知函数fx=|x﹣1|+|x+1|﹣2.1求不等式fx≥1的解集2若关于x的不等式fx≥a2﹣a﹣
已知函数fx=x|x-2|求不等式f-x≤f1的解集.
设函数fx=|x-a|+3x其中a>0.1当a=1时求不等式fx≥3x+2的解集2若不等式fx≤0的
设函数fx=|x﹣a|+3x其中a>0.1当a=1时求不等式fx>3x+2的解集2若不等式fx≤0的
已知函数fx=|x-1|+|x+1|.1求不等式fx≥3的解集;2若关于x的不等式fx>a2-x2+
已知函数fx=|2x+1|+|2x﹣3|.Ⅰ求不等式fx≤6的解集Ⅱ若关于x的不等式fx﹣log2a
热门试题
更多
如图活塞将气缸分成甲乙两气室气缸活塞连同拉杆是绝热的且不漏气以E甲E乙分别表示甲乙两气室中气体的内能则在将拉杆缓慢向外拉的过程中E甲和E乙的变化情况是.
如图所示镜前竖直插两根大头针a和b观察a和b的像重叠在一起的情形其眼睛应放在
如图所示底面积为2×10﹣2m3的圆柱形轻质容器放置在水平桌面上容器内装有适量水质量为0.3kg体积为100cm3金属块与质量为0.5kg木块粘合后漂浮在水面上.过一段时间后金属块与木块分离金属块下沉木块上浮不计粘合剂的质量和体积.求 1分离前金属块和木块排开水的总体积 2分离后木块最终静止时所受到的浮力大小 3分离前后容器底部受到水的压强的变化量.
一只铭牌上标有“6V0.6A”的灯泡接入电路中工作时其两端电压与电流之间的关系的图象如图所示根据图象可以计算出当该灯泡两端电压为4.0V时其电阻大小为8Ω当该小灯泡两端的电压为2V时其消耗的电功率为0.6W.
在图中圆筒的直径d为cm秒表的读数为s.
假定英语课上老师要求同桌之间交换修改作文请你修改你同桌写的以下作文.文中共有10处语言错误每句中最多有两处.每处错误仅涉及一个单词的增加删除或修改. 增加在缺词处加一个漏字符号∧并在其下面写出该加的词. 删除把多余的用斜线划掉. 修改在错的词下划一横线并在该词下面写出修改后的词. 注意 1.每处错误及其修改均仅限一词; 2.只允许修改10处多者从第11处起不计分. Inmyschoolwehaveourowntalentshoweveryyearthathasbeenatraditionfor15years.Thisyearourschoolwasheldoneasscheduled.Agreatmanystudentstookactivepartinit.IdecidedtoplaytheviolinwithapartnernamingJuliawhoplayedthepianoalongforme.Wehadpracticedmanytimebeforethetalentshowstarted. Everyonewatchedtheshowexcited.JuliaandIdidagoodjob.Othersstudentssanganddancedhappily.Thetalentshowhelpedusrelaxbutenrichedourschoollife.Weallenjoyedthemverymuch.
如图所示开关闭合后位于螺线管附近的小磁针N极指向下请在螺线管上画出导线的绕向.
Robotsarenowbeingemployednotjustfordangeroustaskssuchasdiscoveringminesorrescuingpeopleindisasters.Theyarealsofindingapplicationashouseholdhelpsandasnursingassistants.Asincreasingnumbersofmachinesequippedwiththelatestartificialintelligencetakeonagrowingvarietyofspecializedandeverydaytasksthequestionofhowpeopleseethemandbehavetowardsthembecomesevermoreurgent. AteamledbySariNijssenofRadboudUniversityandMarkusPaulusProfessorofDevelopmentalPsychologyatLudwig﹣Maximilians﹣UniversitaetLMUhavecarriedoutastudytodeterminethedegreetowhichpeopleshowconcernforrobotsandbehavetowardsthembasedonmoralprinciples. AccordingtoSariNijssenthestudysetouttoanswerthefollowingquestionUnderwhatcircumstanceswouldadultsbewillingtosacrificerobotstosavehumanlives?Theparticipantswerefacedwithahypothetical假设的moraldilemmaWouldtheybepreparedtoputasinglepersonatriskinordertosaveagroupofinjuredpersons?Inthesituationspresentedtheintendedvictimwaseitherahumanahumanoidrobotthathadbeenhumanized人性化的tovariousdegreesorarobotthatwasclearlyrecognizableasamachine. Thestudysuggestedthatthemoretherobotwashumanizedthelesslikelyparticipantsweretosacrificeit.Situationsthatincludedvividstoriesinwhichtherobotwasdescribedasamercifulbeingorasacreaturewithitsownunderstandingsexperiencesandthou^itsweremorelikelytostopthestudyparticipantsfromsacrificingitintheinterestsofanonymous无名的humans. ThisresultindicatesthatourstudygroupattachedacertainmoralstatustotherobotsaysPau﹣lus.Onepossiblesuggestionofthisfindingisthatattemptstohumanizerobotsshouldnotgotoofar.Sucheffortscouldcomeintoconflictwiththeirintendedfunction﹣tobeofhelptous. 1Whathasbecomeaconcernaboutrobots? A.Howtohumanizethem. B.Howtotreattheminlife. C.Howtousethemeffectively. D.Howtofindmoreapplications. 2Inthestudytheparticipantsprobablyhavetodecide. A.whentosacrificearobot B.wheretoexperiencerisks C.whichrobottoworkwith D.whatrobotsshouldbelike 3WhatcanbeinferredfromPaulus'words? A.Humanizedrobotsofferlesshelptopeople. B.Humanizingrobotstoomuchmaybeimproper. C.Certainmoralstatusshouldbeattachedtorobots. D.Conflictsoftenhappenbetweenhumansandrobots. 4Whichofthefollowingwouldbethebesttitleforthetext? A.RobotsAMustforFuture B.HumanizedRobotsANewTrend C.RobotSavedPeopleTaketheHit D.HumanizedRobotsReplaceHuman
NotallthehistoriansinCanadaarehistoriansofCanada.CaseinpointTimothyBrook. BrookwasbornandschooledinTorontoandhenowteachesinVancouver.Buthe'sahistorianofChinaandhisrecentbookVermeer'sHatseemsatfirsttobeaboutHollandintheperiodoftheDutchmasters.WhenImetBrookrecentlyinVancouverhedidseemtrulyaglobalhistorian.VancouverishishomebutVermeer'sHathasbeenpublishedaroundtheworld. BrookwasjustinfromOxfordUKwherehetaughtpartoftheyearbywayofNewYorkwhereVermeer'sHathadjustbeengiventheLyntonHistoryPrize.HewasabouttogotoCaliforniawherehewasduetolecture.Stilltheauthorandthebook﹣﹣﹣andthehat﹣﹣﹣saysomethingfreshaboutCanadaandtheworld. I'vebeenlookingatVermeersince1971saysBrook.LookingatDutchinterior室内的scenesfromthemid﹣1600shenoticedmapsChineseporcelains瓷器SouthAmericansilverVirginiatobacco﹣allmarkingtheinfluencesofthewideworld.InBrook'stellingVermeer'smasterworksbecomedoorwaystotheworldandnotleasttothelargestrichestnationintheworldtheChinaofthelateMingEmpireafieldinwhichBrookhappenstobeaspecialist. Brookusedglobalhistoryasawaytofindcommongroundwithfellowhistorians.Thesixteenthcenturyistheageofdiscoverybuttheseventeenthcenturyistheageofpeoplestartingtomovethepossibilityofaglobaleconomyinterculturalrelationsacrosstheglobehesaid. ItprovednothardforthisCanadianhistorianoftheworldtofindCanadainworldhistory﹣﹣ortheworldinCanadianhistory.InVermeer's1658paintingofaDutchsoldierinawonderfulhatthefelt毛毡forthehatwasprobablymadeinLachinefromFrenchlaChinemeaningChina.EstablishedinCanadabydeChamplainthetownwassonamedbecauseChamplainlikeotherexplorerstheFrenchexplorerSamuelwashopingtogetthroughCanadatoChina. 1WhichwasthelineofBrook'srecentjourneybackhome. A.Toronto﹣﹣Oxford→Vancouver B.Oxford→NewYork→Vancouver C.California→Toronto→Vancouver D.NewYork→California→Vancouver. 2WhichisdiscussedinBrook'sVermeer'sHat? A.TheLyntonHistoryPrize B.Waystogivegoodlectures C.TheMingDynastyofChina D.AhatVermeerworeforyears 3WhatcanweinferaboutVermeer? A.HewasaDutchpainter B.HewasaFrenchexplorer C.HewasaUKpublisher D.HewasaUSteacher 4Whatcanbesuitabletitleforthetext? A.TheInfluencesofmasters'books B.Anageofmovingandpossibilities C.TheImportanceofCulturalExchange D.ACanadianHistorianThinkingGlobally
Here'salistofbooksI'mlookingforwardtothisfallseason.Notallofthemwillrisetotheleveloftheadvertisementbutit'sanabundantcrop. HomeAfterDarkbyDavidSmallLiverightSept.11 In2009Smallpublishedacelebratedgraphicmemoir回忆录calledStitches.NowtheCaldecottMedalwinnerisbackwithagraphicnovelaboutamotherless13﹣year﹣oldboybroughtupinanunhappyhomeinCalifornia.Thisisataletoldinfewwordsandmanystrikingimages.OnSept.11at3p.m.SmallwillbeatAmazonbooksatUnionMarket.Moreinformationatwww.amazon.com/graph﹣tale. WaitingforEdenbyElliotAckermanKnopfSept.25 ThisbriefnovelisrelatedbyadeadsoldierwhoiswatchingoverahorriblyburnedpartnerinaTexashospital.ThatsoundsembarrassinglyemotionalbutAckermanwhoservedinaNavyinIraqandAfghanistanisoneofthebestsoldier﹣writersofhisgeneration.Moreinformationatwww.amazon.com/military﹣essay. AllYouCanEverKnowbyNicoleChungCatapultOct.2 ChungtheeditoroftheliterarymagazineCatapultwasadoptedasababybyawhitefamilyinOregon.InthismemoirshewritesaboutherchildhoodherAsianAmericanidentityandhersearchfortheKoreanparentswhogaveherup.Moreinformationatwww.amazon.com/politics﹣prose. UnshelteredbyBarbaraKingsolverHarperOct.16 Alternatingbetweenpastandpresentthisnoveltellsthestoryofawomaninvestigatingalate﹣19th﹣centuryscienceteacherwhowascaughtupinthecontroversyoverDarwinism.Likeherothernovelsthisonepromisestoexploresocialandscientificproblems.Visitwww.amazon.com/tech﹣scienceformoreinformation. 1Ifyouhopeforasignatureoftheauthoryouwillprobablybuyacopyof. A.AllYouCanEverKnow B.WaitingforEden C.HomeAfterDark D.Unsheltered 2WhojoinedthearmyandwassenttotheMiddleEast? A.ElliotAckerman. B.DavidSmall. C.BarbaraKingsolver. D.NicoleChung. 3Ifyouwanttoreadbooksaboutnon﹣fictionyoucansurf. A.www.amazon.com/graph﹣tale B.www.amazon.com/politics﹣prose C.www.amazon.com/military﹣essay D.www.amazon.com/tech﹣science
如图所示直流发电机在发电的过程中线圈会受到磁场力的作用选填“会”或“不会”.
利用伏安法测电阻的部分电路如图关于测量误差和产生原因说法正确的是
电源因有内阻在使用时内阻也会分掉一部分电压无内阻分压时的电压称为电源电动势.正在工作的闭合电路中测到的电源两端电压其实是路端电压并非电动势.图中R为已知电阻Rx为待测电阻K1为单刀单掷开关K2为单刀双掷开关V为电压表内阻极大E为电源电阻不可忽略.现用图中电路测量电源电动势e及电阻Rx. 1操作步骤 ①选填“闭合”或“断开”K1K2接到a端记下此时电压表的示数U1即为电源电动势 ②闭合K1K2接到a端记下电压表的读数U2 ③记下电压表的读数U3 2由R及测得的量可得Rx=.
细胞中的糖类大致可分为单糖二糖和多糖等下列物质中属于单糖的是
Inacleanclinicalroommybestfriendwasdyinginmyarms.Hiseyesdarkbrownandtrustingwouldsoon1forever.HeartbrokenIsaidFlashyou2somuchhappinesstome.Iwilldosomethinggoodasa3. Flashcameintomy4whenIwasnine.Fromthemomentrayparentsbroughtthiscutedoghomehe5myfamilywithjoy. Then6happened.MymumwasdiagnosedwithbreastcancerwhenIwas11.Thenmygrandmawhowasmy7passedaway.MysisterdevelopedCrohn'sDiseaseandwhilebeingtested8aheartattack.Iwasbeingbulliedatschoolandstartedto9classesandavoidseeingpeople. Flashsoongaveroeallthe10hecouldoffer.ThereweretimeswhenIfelttherewasno11butapairofbrowneyesandlovingfacewouldsomehowcaseme.Iknewhewas12thereforme.Iknewheunderstood. Nowafter15yearsFlashwas13.Ithoughtdoingcharityworkwasthebestrewardforhim.I14inanon﹣profitorganizationinSouthamptonandcontributedabout3500hoursto15hildrenwithspecialneedswhichcompletelychangedmylife.Ilearnedtolovethe16Ihadbeenonandevenacceptthe17bits. IstillmissFlash.Itwashimthathadsomehow18metohelpingothers.Flash'sdeathwasoneofthe19momentsofmylife.Butitalsoaninspiringmomentthat20whoIwas﹣inthebestpossibleway﹣forever. 1A.open B.close C.shine D.fade 2A.brought B.told C.saved D.owed 3A.relief B.chance C.bonus D.reward 4A.mind B.room C.world D.power 5A.helped B.filled C.protected D.decorated 6A.disasters B.stories C.wonders D.mistakes 7A.burden B.trouble C.strength D.challenge 8A.caused B.noticed C.fought D.suffered 9A.skip B.give C.take D.enjoy 10A.comment B.comfort C.expectation D.relaxation 11A.hope B.time C.money D.use 12A.frequently B.sometimes C.hardly D.always 13A.aging B.gone C.missing D.deserted 14A.searched B.competed C.volunteered D.performed 15A.attendingto B.meetingwith C.talkingabout D.bringingup 16A.earth B.journey C.holiday D.street 17A.fantastic B.absurd C.hard D.pleasant 18A.led B.forced C.trained D.persuaded 19A.fullest B.craziest C.tiniest D.saddest 20A.explained B.transformed C.admitted D.described
下列关于惯性的说法中正确的是
Ifyoufeelsickoruncomfortableyoumightseekoutadoctor.Butwhattodoifyoudon'tquiteknowwhereyoufitintothisworldandyou'retiredofcarryingthatburdenalone? Iansweredstrangers'questionsonlifepuzzlesattheentrancetotheNewYorkCitysubwayat57thand8th.Agroupofstrangershadstoppedbybecausetheywerecarryingaroundsomedeepmeaningfulquestionsthathadlonggoneunansweredlikewhycan'tIbehappierinmylife? AndthenIspottedherwhowouldbemytoughestquestioneroftheday.Shewasabout6yearsoldandheldhermother'shandasshecraned伸长脖子hernecktostareatas.Hermotherstoppedbutthegirlhesitated.It'sOKIoffered.Doyouhaveaquestion?Thegirlsmiledathermotherthenletgoofherhandtowalkovertowardsus.ShelookedmedeadintheeyeandsaidHowdoIknowI'mreal? SuddenlyIwasbackingraduateschool.ShouldItalkabouttheFrenchphilosopherReneDescartestoproveourexistencewiththephraseIthinkthereforeIam?OrmenlionEnglishphilosopherG. Mooreandhisfamousuhereisonehandhereistheothertoprovetheexistenceoftheexternalworld?Butthentheanswercametome.Irememberedthatthemostimportantpartofphilosophywasfeedingoursenseofwonder.CloseyoureyesIsaid.Shedid.Welldidyoudisappear?Shesmiledandshookherheadthenopenedhereyes.Congratulationsyou'rereal. Shegrinned露齿而笑broadlyandwalkedovertohermotherwholookedbackatusandsmiled. 1Whydidtheauthorshowupattheentranceofthesubway? A.Totakethesubway. B.Tolookforstrangers'help. C.Toofferadviceonlifepuzzles. D.Tohelpstrangerscarrytheirbags. 2Whatmadethelittlegirlstareattheauthor? A.Curiosity. B.Horror. C.Excitement. D.Nervousness. 3Howdidthegirlfindtheanswer? A.Byhearingastory. B.Bylearningphilosophy. C.Byreferringtoothers'words. D.Byhavingarealexperience. 4Whichofthefollowingcanbestdescribetheauthor? A.Strictandsmart. B.Honestandbrave. C.Cleverandhelpful. D.Humorousandsociable.
如图所示的电路中闭合开关S电路正常工作发现两只电压表的指针偏转角度相同其中两表均为0~3V和0~15V的双量程电压表则R1R2等于
如图所示水平传送带上的物块A随传送带一起向右做匀速直线运动不计空气阻力下列说法中正确的是
熔化热是指单位质量的晶体在熔化时变成同温度的液体物质所需吸收的热量常见的冰的熔化热是3.36×105J/kg.如图用220V1210W的电饭锅给1Kg零摄氏度的冰加热设加热效率为84%直至沸腾用了15分钟时间设环境为通常状况冰水只吸收电饭锅所给热量且电饭锅的电阻不随温度变化已知C水=4.2×103J/kg•℃. 1求冰融化成水直至沸腾所需的热量 2求电饭锅实际电功率 3求电饭锅的实际电压.
如图甲所示是“测量小灯泡的电功率”的电路图图乙是实物连接图.其中电源是两节新干电池小灯泡的额定电压为2.5V滑动变阻器上标有“10Ω1A”的字样. 1图乙已连接了部分电路请用笔画线代替导线按照电路图将未连接的电路连接完整 2调节滑片使电压表的示数为2.5V此时电流表的示数如图丙所示则该灯泡的额定功率为0.75W 3完成以上实验后进一步测量记录多组实验数据并描绘出小灯泡的电流随其两端电压变化关系的曲线如图丁所示.通过分析处理图象中的有关数据除了可以得到其额定电功率大小之外还可以得到的信息和实验结论是灯丝电阻随温度的升高而增大写出一条即可得分. 4如果某同学在连接好电路后闭合开关在移动滑动变阻器滑片P的过程中发现灯泡变亮时电压表示数变小灯泡变暗时电压表示数变大.经检查所用器材完好出现这种现象的原因是电压表与滑动变阻器并联.
WhenIfirstcametoUKfromChinaat6Ienteredthefirstgrade.1.Isawchildrenthrowtheirleftoverfoodintothelargetrashcans﹣fromhalf﹣eatenpizzastountouchedburgers.Iwatchedthempourtheirmilkintoawhitebucket.InChinathiswasahugeno﹣noinschool.Wehadtofinisheverything. Onedaymyfirstgradeteacherannouncedthatwewouldbehavingapartyandeveryonewastoldtobringsomethingfromtheircountry.2.Mymomstayedupafterherlongdayofworkandmademanydumplings.SheputtheminthefridgeandwokeupearlyinthemorningtosteamthemandfrythemsotheywouldtasteextrafreshwhenIbroughtthemtoschool.Theysmelledgreatandlookedgoldenbrownaftertheywerecooked. Iwassoexcitedtosharethesewithmyclassandteachers.Itwasplacedinthecornerofthetablenexttoalltheotherdeliciousfood.3.OneortwokidsbravelytookapieceandknewwhattheywerebecausetheyhaditwiththeirparentsataChineserestaurant.Attheendofthepartyitwascleanup.MyteacherwalkeduptomeandaskedpointingtothedumplingsWouldyouliketotakethesehome?IcarefullyrepliedNo…4.IthoughtshewasgoingtoshareitwithotherteachersbutimmediatelyafterIsaidthatshethrewallthedumplingsintothetrashandcontinuedcleaning.Iwasconfused;whatjusthappened? 5.AndtodayIstillwitnessthisfrequentlyinmyEnglishfiends.Pleaseeatallyourfoodortakeittogoorshareitorjustgetenoughsoyoudon'thavetothrowitaway.Thankyou. A.InChinanousuallymeansyes B.Igotsuperexcitedandtoldmyparents C.Itwasveryimpolitetotakeyourgifthome D.ThiswasthebiggestcultureshockIhaveexperienced E.WhenIgothomeIsharedtheexperiencewithmyparents F.Manykidshadthecookiesandjuicesandwerehesitanttotrythedumplings G.Ididn'tunderstandwhykidsweregettingtheirlunchfoodandnotfinishingit
Aroundtheworldmalnutrition营养不良hasbecomeaproblemthatcosts﹩3.5trillionperyearaccordingtothelatestGlobalNutritionReport1givesananalysisoffoodandnutritionissueseachyear. Althoughmostcountrieshavefallenshortintheirefforts2dealwithpoornutritionandfoodinsecuritytheUSappearstobebadlyofftrackthereportfound.Theworld's3largeeconomycontinuestosufferfromhighratesofobesitydiabetesandanemia贫血accordingtothedataandhasmorethanamillionoverweightchildren. Malnutritionisresponsibleformoreill﹣health4anyothercause.5healthconsequencesofoverweightandobesitycontributetofourmilliondeaths6globe.CorinnaHawkesdirectoroftheCenterforFoodPolicy7writeinthereport. Accordingtothestudymostcountrieshaveatleasttwoissuesrelatedtomalnutrition.Themostseriousissuesarechildrenwhoareeitheroverweightanemic8sufferfromundevelopedgrowth.Overallmalnutritioncontributestoabouthalfofallchildhooddeathstheresearchshowed.Andthose9affectmaynotbeabletogetasgoodajobastheycouldhaveiftheyhadbeenfedwell.Italsopreventsthem10beabletocontributetosocietyandtheeconomyaswellastheywouldhaveinahealthierenvironment.
假设你是李华你的英国笔友Tony即将完成学业上周他来信就是否到中国工作询问你的意见.请根据以下提示回一封电子邮件内容包括 1建议他来中国就业; 2阐述你的理由就业机会多专业受欢迎不同的文化体验等; 3承诺可以提供帮助. 注意1词数100左右开头和结尾已给出不计入总词数; 2可适当增加细节以使行文连贯. DearTony Yours LiHua
小郑同学利用手边的器材天平和砝码空玻璃瓶足够的水某种液体顺利的完成了测量“某种液体密度”的实验.下面给出的是小郑完成实验时的第一个步骤请你将实验步骤补充完整.已知水的密度为ρ水待测液体足够多 1用调节好的天平和砝码测出空玻璃瓶的质量m0并记录在表格中 2用调节好的托盘天平测量并记录在表格中 3用调节好的托盘天平测量并记录在表格中 液体密度的计算公式ρ液=.
在水平桌面上探究平面镜成像特点的实验装置与实验情景如图所示请完成下列问题 1如图甲所示在实验过程中要用透明的平板玻璃代替平面镜.如果现有5mm厚和2mm厚的两块玻璃板应选择2mm厚的玻璃板做实验其目的是减小玻璃板厚度导致的两个像而产生的重影现象对实验结果的影响. 2如图乙所示如果玻璃板没有与水平桌面竖直放置则在实验操作过程中会出现的情况是桌面上玻璃板后蜡烛无法和玻璃板前蜡烛的像重合 3如图丙所示经过三次实验在正确的实验操作过程中要分别标记像A′B′C′与物ABC相应的位置为了得到更多的实验结论接下来应该进行的实验操作是将像和物位置的对应点相连接其目的是为了判断像物连线与镜面是否垂直以及像和物到平面镜的距离相等.
如果燃烧热值为3×107J/kg的煤加热水若加热过程中效率为20%则需要完全燃烧175g的煤才能使质量为5kg的水温升高50℃水的比热容为4.2×103J/kg•℃.
如图是标准大气压下质量为1g的某液体的体积﹣﹣温度图以下说法正确的是
我们可以用图示的电路图测量未知电阻RX的阻值.调节电路当电压表示数U为3.0V时电流表的示数为0.3A.如果考虑到电流表的电阻值RA为0.5Ω待测电阻RX′的阻值应为Ω.
由金属杆组成如图所示的导轨其中水平面上两平行导轨足够长且全部置于竖直向上的磁场中与倾斜放置的导轨ABCD平滑且固定连接.将一金属棒ab从倾斜导轨上一定高度由静止释放运动过程中始终与导轨垂直接触且不受摩擦因为从能量转化的角度简述理由所以ab棒在水平导轨上的运动情况是选填加速减速或匀速.
热门题库
更多
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
高一上学期生物
高一下学期生物
高二上学期数学
高二上学期物理
高二上学期英语
高二上学期生物
高二下学期数学
高二上学期化学
高二下学期物理
高三下学期物理
高三上学期物理
高三上学期生物