题目内容
质量为m的物体以速度v0竖直向上抛出,物体落回地面时度大小为
,设物体在运动中所受空气阻力大小不变,求:
(1)物体运动过程中所受空气阻力的大小;
(2)若物体与地面碰撞过程中无能量损失,求物体运动的总路程
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824114753128254.gif)
(1)物体运动过程中所受空气阻力的大小;
(2)若物体与地面碰撞过程中无能量损失,求物体运动的总路程
(1)
(2)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824114753160502.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824114753160459.gif)
(1)设阻力大小为f,上升的高度为h ,有动能定理得
解得
(2)由能量守恒知
所以
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824114753175663.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824114753222759.gif)
解得
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824114753160502.gif)
(2)由能量守恒知
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824114753253517.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824114753160459.gif)
![](http://thumb2018.1010pic.com/images/loading.gif)
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