题目内容
力F作用在物体上,F随物体位移L的变化关系如图2所示,那么在物体运动25m的过程中,
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241349504302452.png)
(1)力F对物体做了多少功?
(2)前10m平均速度为5m/s,后15m用3S,则整个过程中F的平均功率为多少?
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241349504302452.png)
(1)力F对物体做了多少功?
(2)前10m平均速度为5m/s,后15m用3S,则整个过程中F的平均功率为多少?
(1)350J
(2)
(2)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241349504931300.png)
解:(1)由图像得,总做功等于所围梯形面积
W=1/2(10+25)20=350J (3分)
(2)
(2分)
(3分)
W=1/2(10+25)20=350J (3分)
(2)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241349505401055.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241349504931300.png)
![](http://thumb2018.1010pic.com/images/loading.gif)
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