题目内容
摆长为l、摆球质量为m的单摆在做最大摆角θ<5°的自由摆动,则在从最高点摆到最低点的过程中( )
A.摆线拉力的冲量为零 |
B.摆球重力的冲量为![]() ![]() |
C.摆球重力的冲量为零 |
D.摆球合外力的冲量为零 |
B
因为θ<5°,摆球做简谐运动,则t=T=![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824114005159233.gif)
,故tG=mgt=![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824114005190382.gif)
,B对.由冲量定义知:A、C、D错.
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824114005159233.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824114005174300.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824114005190382.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824114005128260.gif)
![](http://thumb2018.1010pic.com/images/loading.gif)
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题目内容
A.摆线拉力的冲量为零 |
B.摆球重力的冲量为![]() ![]() |
C.摆球重力的冲量为零 |
D.摆球合外力的冲量为零 |