题目内容
(10分)如下图所示,在倾角a=37°的斜面上有一块竖直放置的挡板,在挡板和斜面之间放有一个m=2kg的光滑圆球,处于平衡状态。
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241320116846981.png)
(1)试画出球体的受力示意图;
(2)求出球体对档板和斜面的压力。(sin37°=0.6,cos37°=0.8,重力加速度g取 10m/s2)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241320116846981.png)
(1)试画出球体的受力示意图;
(2)求出球体对档板和斜面的压力。(sin37°=0.6,cos37°=0.8,重力加速度g取 10m/s2)
解:(1)球体受力如图所示
球受到斜面的支持力为N1,球受到挡板的压力为N2,(2分)
(2)小球的受力分析如右图所示,由共点力的平衡条件可得:
N2=N1sin37° ①(1分)
G=N1cos37° ②(1分)
根据牛顿第三定律,球对挡板的压力
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824132011731512.png)
球体对斜面的压力
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824132011762469.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824132011793169.png)
联合以上各式解得:
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824132011840585.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824132011871588.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241320119348010.png)
略
![](http://thumb2018.1010pic.com/images/loading.gif)
练习册系列答案
相关题目