题目内容
如图所示,从倾角为θ的足够长的斜面顶端P处以水平速度v0抛出一个小球,小球落在斜面上某处Q点,落在斜面上的速度方向与斜面间的夹角为α,若把小球初动能变为2倍,则下列说法正确的是
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250011196132812.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250011196132812.png)
A.小球在空中运动时间变为原来的![]() |
B.α角将变大 |
C.PQ间距一定等于原来间距的4倍 |
D.α角与初动能大小无关 |
AD
试题分析: 根据
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001119644753.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250011196601021.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001119628344.png)
由tan(O+α)=
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001119706647.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001119722780.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001119628344.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001119628344.png)
![](http://thumb2018.1010pic.com/images/loading.gif)
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