题目内容
(9分)滑雪者从高坡雪道上的A点由静止自由滑下,雪道的BC段为水平,CE段为倾角为37°的斜坡,滑雪者滑下从C点水平飞出后落在斜坡上。已知斜坡上C、D间距为L1= 12m,D、E间距为L2= 36m,从A到C克服摩擦力做功等于重力做功的K倍,K= 0.20,sin37° = 0.6,cos
37° = 0.8,不计空气阻力,为了能落在坡上DE之间,滑雪者开始滑下的A点距BC水平面的高度h应满足什么条件?(结果保留两位有效数字)![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241223210972584.jpg)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/2014082412232108172.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241223210972584.jpg)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122321113554.gif)
由A至C依动能定理
(2分)
从C平抛,设落点与C相距![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122321144185.gif)
竖直方向
(1分)
水平方向
(1
分)
由以上得:
(2分)
应满足:
(2分)
得:
(1分)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122321128701.gif)
从C平抛,设落点与C相距
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122321144185.gif)
竖直方向
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122321159634.gif)
水平方向
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122321175531.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/2014082412232119165.gif)
由以上得:
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122321206783.gif)
应满足:
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122321222351.gif)
得:
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824122321113554.gif)
![](http://thumb2018.1010pic.com/images/loading.gif)
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