题目内容
如图a所示,倾角为45°、高为h的斜面固定在水平地面上,小球从高为H(2h>H>h)的某处自由下落,与斜面碰撞(无能量损失)后做平抛运动。若小球做平抛运动后能直接落到水平地面上,自由下落的起始点距斜面左端的水平距离x应满足的条件是 (用符号表示);若测得x=1m时,小球平抛运动的水平射程s最大,且水平射程的平方s2与x关系如图b所示,则斜面的高h应为 m。![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241918360262959.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241918360262959.png)
h>x>h-
H,4
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824191836353346.png)
试题分析:根据题述,h>x 。要使小球做平抛运动后能直接落到水平地面上,s>h-x,s=vt,h-x=
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824191836634338.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824191836353346.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824191836353346.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824191836634338.png)
点评:本题难度较小,平抛运动中注意小球落在斜面上的临界条件,合位移与分位移的关系
![](http://thumb2018.1010pic.com/images/loading.gif)
练习册系列答案
相关题目