题目内容
如图所示,空间的虚线框内有匀强电场,
.
.
是该电场的三个等势面,相邻等势面间的距离为0.5
,其中
为零势面。一个质量为
,带电荷量为
的粒子沿
方向以初动能
自图中的
点进入电场,刚好从
点离开电场。已知
,粒子的重力忽略不计,下列说法中正确的是: ( )
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241309032075132.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130902849366.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130902864370.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130902895377.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130902927382.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130902864370.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130902989346.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130903020314.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130902849366.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130903098393.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130903129296.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130903161343.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130903176643.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241309032075132.png)
A.该粒子到达![]() ![]() |
B.该粒子到达![]() ![]() |
C.该粒子在![]() ![]() |
D.该粒子通过零势面时的动能是1.25![]() |
AC
由P到
,水平方向做匀速直线运动,竖直方向做初速度为0的匀加速直线运动,水平位移为竖直位移的2倍,
,所以
竖直分速度为
,合速度为
,到达
点时的动能是2
,A对。由P到
,动能增量为
,经
等势面时动能增量为0.5
,动能为1.5
,D错。电势能为0,总能量为1.5
。根据能量守恒,到达
时的动能为2
,电势能为-0.5
,B错。在P点时,动能为
,电势能是0.5
,C对。
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130903161343.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130903535723.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130903161343.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130903613323.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130903660468.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130903161343.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130903098393.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130903161343.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130903098393.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130902864370.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130903098393.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130903098393.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130903098393.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130903161343.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130903098393.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130903098393.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130903098393.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824130903098393.png)
![](http://thumb2018.1010pic.com/images/loading.gif)
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