首页
试卷库
试题库
当前位置：
X题卡
>
所有题目
>
题目详情
如图，一架长2.5米的梯子AB斜靠在墙上，已知梯子底端B到墙角C的距离为1.5米，设梯子与地面所夹的锐角为α，则cosα的值为（ ）
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
一架云梯长25米如图斜靠在一面墙上梯子的底端离墙7米如果梯子的顶端下滑了4米那么梯子的底端在水平方向
一架方梯长25米如图斜靠在一面墙上梯子底端离墙7米1这个梯子的顶端距地面有多高2如果梯子的顶端下滑了
一架方梯AB长25米如图所示斜靠在一面上1若梯子底端离墙7米这个梯子的顶端距地面有多高2在1的条件下
.如图一架2.5米长的梯子AB斜靠在一竖直的墙AC上这时梯子的顶端A.到墙底端C.的距离为2.4米如
如图一架梯子斜靠在墙上若梯子底端到墙的距离=3米则梯子长AB=米.
如图一架长5m的梯子斜靠在墙上梯子的底端与墙的距离是3m如果梯子底端向右滑动的距离与梯子顶端向下滑动
如图一架梯子AB长13米斜靠在一面墙上梯子底端离墙5米.1这个梯子的顶端距地面有多高2如果梯子的顶端
如图一架2.5米长的梯子AB斜靠在一竖直的墙AC上这时梯足B.到墙底端C.的距离为0.7米如果梯子的
一架长为10米的梯子斜靠在墙上梯子的顶端距地面的垂直距离为6米如果梯子的顶端沿墙壁下滑1米那么梯子的
等于1米
大于1米
小于1米
不能确定
如图所示一架梯子斜靠在墙上若梯子底端到墙的距离AC＝3米cos∠BAC＝则墙高BC＝________
如图一架云梯长25米斜靠在一面墙上梯子底端离墙7米1这个梯子的顶端距地面有多高2如果梯子的顶端下滑4
一架云梯长25米斜靠在一面墙上梯子底端离墙7米12分1这个梯子的顶端距地面有多高?2如果梯子的顶端下
如图一架长为5米的梯子AB斜靠在与地面OM垂直的墙ON上梯子底端距离墙ON有3米①求梯子顶端与地面的
一架4.1米长的梯子斜靠在一竖直的墙上这时梯子底端距墙角0.9米那么梯子顶端与地面的距离是米．
一架方梯长25米如图斜靠在一面墙上梯子底端离墙7米1这个梯子的顶端距地面有多高2如果梯子的顶端下滑
如图一架梯子AB斜靠在一面墙上底端B.与墙角C.的距离BC为1米梯子与地面的夹角为求梯子的长度精确到
如图一架2.5米长的梯子AB斜靠在竖直的墙AC上这时梯子底部B.到墙底端的距离为0.7米考虑爬梯子的
一架方梯长25米如图斜靠在一面墙上梯子底端离墙7米1这个梯子的顶端距地面有多高2如果梯子的顶端下滑了
如图1－23所示一架梯子斜靠在墙上若梯子底端到墙的距离AC=3米cos∠BAC＝则梯子AB的长度为米
如图一架长25米的梯子斜靠在竖直的墙上这时梯子底端离墙7米.1此时梯子顶端离地面多少米2若梯子顶端下
热门试题
更多
1分Ithinkit'sreallyhardworkformetofinishthejobintwentyminutes. A.a B.an C.the D.不填
5分Therearealotofschoolrulesaroundtheworld.ForexampleinAustraliaCanadaJapanandtheUnitedStatesstudentshavetowearuniformsandtheyarenotallowedtowearearrings. SomeschoolsinJapanandothercountrieshaverulesabouthair.Forexamplestudentsarenotallowedtochangethecoloroftheirhair.IntheUnitedStatesboyscannothavetheirhairgrowlong. ForsafetyatsomeUSschoolsstudentsmusthaveapairofindoorshoesatschooleveryday.Thismakessurestudentswon'tfalloveronthewetfloorsandkeepstheschoolsclean. GumchewingisnotallowedinmanyUSschoolbuildingsasitisdifficulttocleanup.Andifstudentschewguminclasstheymaynotpaymuchattentiontotheirstudies. Inmostforeigncountriesschoolstudentsareallowedtoworkpart﹣time.ButdifferentlyJapaneseschoolstudentsarenotallowedtoworkpart﹣timeorchangethecoloroftheirhair. 41.Whichcountriesshouldstudentsnotbeallowedtowearearringsin A.EnglandandJapan. B.AustraliaandJapan. C.CanadaandChina D.TheUSAandFrance. 42.ArestudentsallowedtochangethecoloroftheirhairinJapan A.Yestheyaren't. B.Notheyare. C.Yestheyare. D.Notheyaren't 43.WhymuststudentshaveapairofindoorshoesatschooleverydayatsomeUSschools A.Thismakesstudentsexercisemoreeasily. B.Thismakesstudentswon'tfalloveronthewetfloors. C.Thiskeepstheschoolsclean. D.Thiskeepstheschoolscleanandmakesstudentssafe. 44.Whatmayhappenifstudentschewguminclass A.Itisdifficulttocleanup. B.Studentswillfalloverintheclassroom. C.Studentsmaynotpaymuchattentiontotheirstudies. D.Theteacherswillbeveryangry. 45.Whatshouldn'tthestudentsbeallowedtodoinJapan A.Theyaren'tallowedtochewgum. B.Theyaren'tallowedtowearuniforms. C.Theyarenotallowedtoworkpart﹣timeorchangethecoloroftheirhair. D.Theyarenotallowedtoeatintheclassroom.
向盛有氯化亚铁和氯化铜混合溶液的烧杯中加入一定量的锌粉充分反应后得到固体M和溶液N．下列叙述错误的是
1分﹣﹣﹣Thanksforaskingmeyourparty. ﹣﹣﹣. A.Nevermind B.Don'tsayso C.Mypleasure D.Yesplease
10分在下面的空白处填入适当的话语话语可以是句子短语或词 ABobwhatareyoudoingB61.Theletterisaboutbadhabits. AWhatdoyoumean BIseesomepeoplethrowlitteraround.Andsomeoftenwastewater.Youknowwaterisveryimportanttous.AYouareright.62 BTotheTVstation.Ihopetheycancallonpeopletoprotectourenvironment AThenwhatshouldwedotoprotectourenvironment BI'dliketogotothePeople'sParkwithmyfriendsthisSaturday.63 AYesI'mfree.64BWe'regoingtocollectrubbishthere. AGoodidea!I'dliketojoinyou.65 BWe'llmeetat8o'clockatthegateofthepark.Seeyouthen!ASeeyou. 61. 62. 63. 64. 65.
不同温度下碳酸钠和碳酸氢钠的溶解度如表所示 1碳酸钠碳酸氢钠俗称小苏打请在选择的物质下面划线． 2服用碳酸氢钠治疗胃酸过多时胃液的pH填“增大”“减小”或“不变”发生反应的化学方程式是． 3为区分碳酸钠和碳酸氢钠两种白色固体．在20℃时各盛有50mL水的甲乙两烧杯中分别加入等质量的碳酸钠和碳酸氢钠固体充分溶解后现象如图所示．乙烧杯中加入的物质是填化学式加入的质量m的范围为．
现有下列四组物质①乙炔C2H2和苯C6H6②乳酸C3H6O3和果糖C6H12O6③丁烷C4H10和乙醚C4H10O④甲苯C7H8和甘油C3H8O3．当总质量一定时各组中的两种物质无论按何种质量比混合完全燃烧生成水的质量均相同．符合该条件的共有
1分Weallourcountrytobestrongerandstronger. A.hope B.wish C.think D.like
科学家用单个分子制成的“纳米车”能在人工操纵下运输药物分子到病源处释放杀死癌细胞．下列叙述错误的是
1分Mr.Kingdidn'tknowyesterdayevening. A.whendoeshissoncomehome B.whendidhissoncomehome C.whenhissoncomeshome D.whenhissoncamehome
投放废旧电池的垃圾收集箱上应贴有的标志是
1分Themeetingisveryimportant.Webelate. A.needn't B.can't C.maynot D.mustn't
逻辑推理是化学学习常用的思维方法．下列推理正确的是
如表是部分碱酸盐的溶解性表20℃中的一部分据此判断下列有关①处物质的说法错误的是
1分youhurryupyou'llbelateforschool A.unless B.as C.if D.until
在氯化钠固体中加入下列物质后既能融化冰雪又能作为复合肥料的是
以化合价为纵坐标以物质的类别为横坐标所绘制的图象叫价类图如图为氮的价类图请分析该图后填写 1写出A点对应物质的化学式找出与图中的点对应物质不相符的化学式． 2在纯净物中根据可以把他们分成单质和化合物． 3写出由BC点对应的两种物质反应的化学方程式．
2分我们都坚信钓鱼岛属于中国.WeallbelievethatDiaoyuislandChina.
电视节目荒野求生中的生命吸管如图所示是一种将污水净化为饮用水的吸管装置可以除去99.3%的细菌和病毒但难以除去汞等金属离子．回答下列问题 1汞等金属离子危害人体健康的原因是． 2生命吸管“能”或“不能”使硬水软化．家庭中使硬水软化一般采取方法． 3吸管中活性炭主要用来除去．碘主要起到杀菌消毒作用生活中消毒还可采用84消毒液有效成分是次氯酸钠NaClO杀菌原理是与空气中的二氧化碳和水反应生成碳酸氢钠和次氯酸HClO试写出反应方程式．
1分Theriversmellsterrible.Peopledirtythingsintoit. A.muststoptothrow B.muststopfromthrowing C.mustbestoppedtothrow D.mustbestoppedfromthrowing
下列食物主要提供蛋白质的是
5分WhatareyougoingtodoifyouareinaburninghouseHowwillyouescapeDoyouknowhowtosaveyourselfPleasereadthefollowingpassage. Escapingafireisaseriousmatter.Knowingwhattododuringafirecansaveyourself.Itisimportanttoknowthewaysyoucanuseandtoshowthemtoeveryoneinthefamilysuchasstairways楼梯andfireescapesbutnotlifts. Fromthelowerfloorsofthebuildingsescapingthroughwindowsispossiblelearnthebestwayofleavingthroughwindowswiththeleastchanceofseriousinjury伤害. Thesecondfloorwindowisusuallynotveryhighfromtheground.Anaverage普通的personhangingbythefinger﹣tips手指尖willhaveadropofaboutsixfeettotheground.Itisabouttheheightofanaverageman.Ofcourseitissafertojumpashortwaythantostayinaburningbuilding. Windowsarealsousefulwhenyouarewaitingforhelp.Besuretokeepthedoorclosed.Orsmokeandfiremaybedrawn向某方向移动intotheroom.Keepyourheadlowatthewindowtobesureyougetfreshairratherthansmokethatmayhaveleaked泄露intotheroom. Onasecondorthirdfloorthebestwindowsforescapearethosewhichopenontoaroof屋顶.Fromtheroofapersoncandroptothegroundmoresafely.Droppingontocement水泥mightendininjury.Bushesandgrasscanhelptobreakafall. 51.Itisimportantto. A.knowthewaystoescapeafire B.putoutafireinaburninghouse C.jumpoutofaburninghouse D.keepthedoorclosed 52.Itispossibletoescapethroughthewindows.. A.ifyouarestrongenough B.iftherearesomebushesontheground C.ifyouliveonalowerfloor D.ifyouhavealongrope 53.Whichofthefollowingwaysofescapingisnotright. A.Youcanescapethroughstairways B.usealifttocomedownatonce C.Escapethroughthewindowswhichopenontoaroof D.Youcanchoosefineescapes 54.Keepyourheadlowatthewindowsothatifthebuildingisonfire A.youcangetfreshair B.youcancallforhelp C.youcaneasilyjumpoff D.youcanbeseenfirst 55.Thebesttitleforthepassageis. A.Escapingthroughthewindows B.SaveYourselffromABurningHouse C.Knowledgeonfire D.WaitingforHelp.
1分﹣Canyouguessthenewschoolbagyesterday ﹣SorryI'venoidea. A.howmuchdidhepayfor B.howmuchhespent C.howmuchhepaidfor D.howmuchdidhespend
在一般条件下下列物质间的转化不能一步实现的是
判断下列大小或强弱关系并用“＜“＞”或“＝”填空． 1溶解度40℃的氢氧化钙20℃的氢氧化钙 2热稳定性碳酸钙碳酸氢铵 3热值氢气甲烷 4pHω＝10%的氯化钠溶液ω＝3%的苛性钠溶液．
1分Whereyou A.havebeento B.havegoneto C.havebeen D.havegone
15分WhenyouwereyoungwhorodeyouaroundonthebackofhisbikeWho21soccerandflewkites22withyouintheparkWhohelpedyouwithyourfirstdifficultmathproblemWhotaughtyouthedifferencesbetween23Yourdad.Nowitisyourturntodosomethingforhim.ThisSundayJune16itisFather'sDay.Sowhynotdo24specialtothankyourdadforallhisencouragementandsupport支持 TheideaofFather'sDaycame25anAmericanladycalledSonoraSmartDoddin1909.Shewantedan26daytohonorherfather.Heraisedsixchildrenbyhimself27hiswifediedduringthebirthoftheirsixthchild.Doddthoughtthereneededtobeadaytohonorhercourageous勇敢的selflessandlovingdad.HerfatherwasbornonJune1928shechosetoholdthefirstFather'sDaycelebrationonhisbirthdayin1910.In1924USPresidentCalvinCoolidgelikedtheideaofanationalFather'sDay.Finallyin1966thethirdSundayinJunewasdeclared宣布Father'sDay. Therearemanywaystoshowyourloveandthanks. Sendhimagreetingcard.Usuallyfathersprefercardsthatarenot29emo﹣ tional使人动感情的.Thereforeperhapschooseonethat30himlaugh. Asmallpresentsuchasaphotoofyourfamily31aspecialwallet32makehimfeellikeaking. Sendhim33andtheredroseisthe34giftintheofficeduringFather'sDay. Ifhehasa35coverhisdesktop桌面withwordslikeIloveyoudad! 21.A.played B.bought C.sold D.gave 22.A.quietly B.sadly C.happily D.loudly 23.A.oldandyoung B.bigandsmall C.rightandwrong D.longandshort 24.A.nothing B.something C.everything D.anything 25.A.in B.out C.over D.from 26.A.easy B.unusual C.strange D.attractive 27.A.when B.until C.after D.before 28.A.so B.because C.until D.if 29.A.much B.also C.many D.too 30.A.willmake B.ismaking C.hasmade D.ismade 31.A.but B.or C.yet D.and 32.A.should B.can C.must D.need 33.A.clothes B.books C.flowers D.computers 34.A.morepopular B.muchpopular C.mostpopular D.popularest 35.A.watch B.computer C.car D.bike.
某工厂产生的烧渣主要含FeOFe2O3还有一定量的SiO2可用于制备七水合硫酸亚铁晶体FeSO4•7H2O其工艺流程如图． 查阅资料SiO2不溶于水也不与稀硫酸反应． 1“浸取”步骤中FeOFe2O3和稀硫酸发生反应的化学方程式分别为 FeO+H2SO4═Fe3O4+H2O． 2过滤用到的玻璃仪器有． 3“还原”步骤是将Fe转化为Fe2+试剂X可用SO2或Fe． ①若试剂X是SO2转化原理为SO2+FeSO43+2H2O＝2FeSO4+2Y则Y的化学式是． ②若试剂X是Fe转化原理的化学方程式为． 测得“还原”后溶液的pH明显增大其原因是．
1分Theoldshouldwell. A.betakecareof B.lookafter C.belookedafter D.betakingcareof
聚乳酸[C3H4O2m]是一种可降解塑料降解生成CO2和H2O．下列叙述错误的是
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
教案备课库
高一下学期数学
教案备课库
高一上学期数学
高一上学期化学
教案备课库
教案备课库
湘公网安备 43130202000226号