题目内容
如图所示,让摆球从图中的A位置开始下摆,正好摆到最低点B位置时线被拉断.设摆线长l,悬点到地面的竖直高度为3l,绳子能承受的最大拉力为5mg,不计空气阻力,求:
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241328392471618.png)
(1)摆球落地时的速度.
(2)落地点D到C点的距离(g=10 m/s2).
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241328392471618.png)
(1)摆球落地时的速度.
(2)落地点D到C点的距离(g=10 m/s2).
(1)
(2)4l
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824132839325540.png)
(1)摆到最低点B位置时线被拉断,有:
, ![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824132839403553.png)
小球做平抛运动的时间为
,竖直速度为![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824132839496723.png)
运动到D点的速度为:![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824132839543894.png)
(2)落地点D到C点的距离
。
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824132839371808.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824132839403553.png)
小球做平抛运动的时间为
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824132839465620.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824132839496723.png)
运动到D点的速度为:
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824132839543894.png)
(2)落地点D到C点的距离
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241328395741017.png)
![](http://thumb2018.1010pic.com/images/loading.gif)
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