题目内容
如图所示,倾角为θ的斜面上固定有一垂直斜面的挡板,重力为G的光滑小球静止时,挡板对球的弹力大小为FN1,斜面对球的弹力大小为FN2,则( )
![](http://thumb.1010pic.com/pic2/upload/papers/20140610/201406102242255883977.png)
A.FN1=Gsinθ | B.FN1=Gtanθ | C.FN2=Gsinθ | D.FN2=
|
![](http://thumb.1010pic.com/pic2/upload/papers/20140610/201406102242255883977.png)
对小球受力分析,受重力、挡板的支持力、斜面的支持力,如图所示
![](http://thumb.1010pic.com/pic2/upload/papers/20140610/2014061022422599414988.png)
根据平衡条件,有:
FN1=Gtanθ
FN2=
故选:BD.
![](http://thumb.1010pic.com/pic2/upload/papers/20140610/2014061022422599414988.png)
根据平衡条件,有:
FN1=Gtanθ
FN2=
G |
cosθ |
故选:BD.
![](http://thumb2018.1010pic.com/images/loading.gif)
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