题目内容
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241203053872633.jpg)
(1)弹簧在此过程做的负功,大小为2J 2 J(2)K=180N/m
(1)小球从A至B过程中,取小球下落的最低点B为零势能点,
依机械能守恒定律:
可得:EP弹="2" J ,所以弹簧在此过程做的负功,大小为2J
(2)在B点:ΔX=(0.5-0.3)m="0.2" m,
可得K=180N/m
依机械能守恒定律:
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824120305434760.gif)
可得:EP弹="2" J ,所以弹簧在此过程做的负功,大小为2J
(2)在B点:ΔX=(0.5-0.3)m="0.2" m,
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824120305434692.gif)
![](http://thumb2018.1010pic.com/images/loading.gif)
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