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如图所示,实线表示某电场中的电场线,但方向未知,虚线是某一带负电的粒子通过该电场区域的运动轨迹,A、B是运动轨迹上的两点.若带电粒子在运动中只受电场力作用,在A、B两点的电势分别为φA、φB,加速度...
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高三下学期物理《》真题及答案
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某同学在研究电子在电场中的运动时得到了电子由a点运动到b点的轨迹图中实线所示图中未标明方向的一组虚线
如果图中虚线是电场线,电子在a点动能较小
如果图中虚线是等势面,电子在a点动能较小
不论图中虚线是电场线还是等势面,a点的场强都大于b点的场强
不论图中虚线是电场线还是等势面,a点的电势都高于b点的电势
如图所示实线为不知方向的三条电场线从电场中M.点以相同速度垂直于电场线方向飞出ab两个带电粒子仅在电
a一定带正电,b一定带负电
a的速度将减小,b的速度将增加
a的加速度将减小,b的加速度将增加
两个粒子的动能,一个增加一个减小
如图所示实线表示在竖直平面内的电场线电场线与水平方向成α角水平方向的匀强磁场与电场正交有一带电液滴沿
液滴一定做匀速直线运动
液滴一定带正电
电场线方向一定斜向上
液滴有可能做匀变速直线运动
如图所示实线表示某静电场的电场线虚线表示该电场的等势面.下列判断正确的是
1、2两点的场强相同
2、3两点的场强相同
1、2两点的电势相等
2、3两点的电势相等
如图所示实线为方向未知的三条电场线ab两带电粒子从电场中的O.点以相同的初速度飞出.仅在电场力作用下
a一定带正电,b一定带负电
a电势能减小,b电势能增大
a加速度减小,b加速度都增大
a和b的动能一定都增大
在一些电磁现象中会产生一种特殊的电场其电场线为一个个同心圆没有起点和终点如图所示实线为电场线方向为顺
M.点的场强比N.点的场强大
M.点的电势比N.点的电势高
将一点电荷沿直线从M.点移到N.点,电势能不变
将一点电荷从M.点由静止释放,点电荷会沿电场线做圆周运动
如图所示实线为不知方向的三条电场线从电场中M.点以相同速度垂直于电场线方向飞出ab两个带电粒子仅在电
a一定带正电,b一定带负电
a的速度将减小,b的速度将增加
a的加速度将减小,b的加速度将增加
两个粒子的动能,一个增加一个减小
如图所示实线表示某静电场的电场线虚线表示该电场的等势面.下列判断正确的是
1、2两点的场强相等
1、3两点的场强相等
1、2两点的电势相等
2、3两点的电势相等
如图所示实线表示某静电场的电场线.虚线表示该电场的等势面ab是电场中的两点.以下判断正确的是
a点的场强大于b点的场强
a点的电势高于b点的电势
正电荷在a点的电势能大于在b点的电势能
将负电荷从a点移到b点电场力对其做正功
如图所示实线表示在竖直平面内的电场线电场线与水平方向成α角水平方向的匀强磁场与电场正交有一带电液滴沿
液滴一定做匀速直线运动
液滴一定带正电
电场线方向一定斜向上
液滴有可能做匀变速直线运动
如图所示实线表示处在竖直平面内的匀强电场的电场线与水平方向成角水平方向的匀强磁场与电场正交有一带电
液滴一定做匀速直线运动
液滴一定带正电
电场线方向一定斜向上
液滴有可能做匀变速直线运动
如图所示虚线为某一带电粒子只在电场力作用下的运动轨迹M.N.为运动轨迹上两点下列说法中正确的是
如果实线表示电场线,则该粒子在M.点的动能一定小于在N.点的动能
如果实线表示等势面,则该粒子在M.点的动能一定小于在N.点的动能
不论实线表示电场线还是等势面,粒子在M.点的加速度 一定小于在N.点的加速度
不论实线表示电场线还是等势面,都不能确定M.、N.两点电势高低关系,但能确定该粒子所带电荷的正负
如图所示实线表示在竖直平面内匀强电场的电场线电场线与水平方向成α角水平方向的匀强磁场与电场正交有一带
液滴一定做匀变速直线运动
液滴一定带正电
电场线方向一定斜向上
液滴一定做匀速直线运动
某同学在研究电子在电场中的运动时得到了电子由a点运动到b点的轨迹图中实线所示图中未标明方向的一组虚线
如果图中虚线是电场线,电子在a点动能较大
如果图中虚线是等势面,电子在b点动能较小
不论图中虚线是电场线还是等势面,a点的场强都大于b点的场强
不论图中虚线是电场线还是等势面,a点的电势都高于b点的电势
如图所示实线为不知方向的三条电场线从电场中M.点垂直于电场线以相同速度飞出ab两个带电粒子运动轨迹如
能判断a、b一定带异种电荷,但是不能判断电场的方向
两个粒子的电势能一个增加一个减小
a的加速度将减小,b的加速度将增加
如果知道a带正电,该电场线可能是带正电的点电荷产生的电场
如图所示图中实线表示一匀强电场的电场线一带负电荷的粒子射入电场虚线是它的运动轨迹ab是轨迹上的两点若
电场线方向向下
粒子一定从a点运动到b点
a点电势比b点电势高
粒子在a点的电势能大于在b点的电势能
带箭头的实线表示某一电场的的电场线虚线MN为带电粒了在电场力作用下的运动轨迹如图所示则粒子在点的电势
如图所示虚线为某一带电粒子只在电场力作用下的运动轨迹M.N.为运动轨迹上两点下列说法中正确的是
如果实线表示电场线,则该粒子在M.点的动能一定小于在N.点的动能
如果实线表示等势面,则该粒子在M.点的动能一定小于在N.点的动能
不论实线丧示电场线还是等势面,粒子在M.点的加速度一定小于在N.点的加速度
不论实线表示电场线还是等势面,都不能确定M.、N.两点电势高低关系,但能确定该粒子所带电荷的正负
如图所示实线表示在竖直平面内匀强电场的电场线电场线与水平方向成α角水平方向的匀强磁场与电场正交有一带
液滴一定做匀变速直线运动
液滴一定带负电
电场线方向一定斜向上
液滴一定做匀速直线运动
如图所示实线表示在竖直平面内的匀强电场的电场线电场线与水平方向的夹角为α水平方向的匀强磁场与电场线正
液滴一定做匀速直线运动
液滴一定带正电
电场线方向一定斜向上
液滴也有可能做匀变速直线运动
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已知椭圆的离心率为以该椭圆上的点和椭圆的左右焦点F1F2为顶点的三角形的周长为.1求椭圆C的标准方程2设该椭圆C与y轴的交点为MN点M位于点N的上方直线y=kx+4与椭圆C相交于不同的两点AB求证直线MB与直线NA的交点D在定直线上.
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设xy满足约束条件则目标函数z=x+y取最小值时的最优解是
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设M为平行四边形ABCD对角线的交点O为平行四边形ABCD所在平面内任意一点则λ=.
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若且则cos2α=.
设集合A={124}B={x|x2﹣4x+m=0}.若A∩B={1}则B=
不等式|x﹣1|≤5的解集为.
在直角坐标系xOy中曲线C1的参数方程为α为参数将曲线C1上各点的横坐标都缩短为原来的倍纵坐标坐标都伸长为原来的倍得到曲线C2在极坐标系与直角坐标系xOy取相同的长度单位且以原点O为极点以x轴非负半轴为极轴中直线l的极坐标方程为. 1求直线l和曲线C2的直角坐标方程 2设点Q是曲线C2上的一个动点求它到直线l的距离的最大值.
设ω>0函数y=sinωx++2的图象向右平移个单位后与原图象重合则ω的最小值是
已知△ABC的面积是AB=1则AC=
AnewcollectionofphotosbringsanunsuccessfulAntarcticvoyagebacktolife.FrankHurley'spictureswouldbeoutstanding﹣﹣﹣﹣undoubtedlyfirst﹣ratephoto﹣journalism﹣﹣﹣iftheyhadbeenmadelastweek.Infacttheywereshotfrom1914through1916mostofthemafteradisastrousshipwreck海难byacameramanwhohadnoreasonableexpectationofsurvival.Manyoftheimageswerestoredinanicechestunderfreezingwaterinthedamagedwoodenship.TheshipwastheEnduranceasmalltightNorwegian﹣builtthree﹣masterthatwasintendedtotakeSirErnestShackletonandasmallcrewofseamenandscientists27meninalltothesouthernmostshoreofAntarctica'sWeddellSea.FromthatpointShackletonwantedtoforceapassagebydogsled雪橇acrossthecontinent.ThejourneywasintendedtoachievemorethanwhatCaptainRobertFalconScotthaddone.CaptainScotthadreachedtheSouthPoleearlyin1912buthaddiedwithhisfourcompanionsonthemarchback.AswriterCarolineAlexandermakesclearinherforcefulandwell﹣researchedstoryTheEnduranceadventuringwaseventhenathoroughlycommercialeffort.Scott'slastjourneycompletedasbelayinatentdyingofcoldandhungercaughttheworld'simaginationandafilmmadeinhishonordrewcrowds.ShackletonaonetimeBritishmerchant﹣navyofficerwhohadgottowithin100milesoftheSouthPolein1908startedabusinessbeforehis1914voyagetomakemoneyfrommovieandstillphotography.FrankHurleyaconfidentandgiftedAustralianphotographerwhoknewtheAntarcticwashiredtomaketheimagesmostofwhichhaveneverbeforebeenpublished.33.WhatdoweknowaboutthephotostakenbyHurley?A.TheyweremadelastweekB.TheyshowedunderseasceneriesC.TheywerefoundbyacameramanD.Theyrecordedadisastrousadventure34.WhoreachedtheSouthPolefirstaccordingtothetext?A.FrankHurleyB.ErnestShackletonC.RobertFalconScottD.CarolineAlexander35.WhatdoesAlexanderthinkwasthepurposeofthe1914voyage?A.ArtisticcreationB.ScientificresearchC.MoneymakingD.Treasurehunting.
不等式的解集为
已知函数求函数fx的单调区间与极值.
2017年5月14日第一届“一带一路”国际高峰论坛在北京举行为了解不同年龄的人对“一带一路”关注程度某机构随机抽取了年龄在15﹣75岁之间的100人进行调查经统计“青少年”与“中老年”的人数之比为911. 1根据已知条件完成上面的2×2列联表并判断能否有99%的把握认为关注“一带一路”是否和年龄段有关 2现从抽取的青少年中采用分层抽样的办法选取9人进行问卷调查.在这9人中再选取3人进行面对面询问记选取的3人中关注“一带一路”的人数为X求X的分布列及数学期望. 附参考公式其中n=a+b+c+d 临界值表
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