题目内容
小球以15 m/s的水平初速度向一倾角为37°的斜面抛出,飞行一段时间后,恰好垂直撞在斜面上。求:
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241240093581947.gif)
(1)小球在空中的飞行时间;
(2)抛出点距落球点的高度。(sin370="0.6 " cos370=0.8)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241240093581947.gif)
(1)小球在空中的飞行时间;
(2)抛出点距落球点的高度。(sin370="0.6 " cos370=0.8)
解:将球垂直撞在斜面上的速度分解,如图6-4-7所示.由图可知
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241240093897583.jpg)
θ=37°,φ=90°-37°=53°……2分
tanφ=
,则t=
·tanφ=
s="2" s……4分
h=
×10×22 m="20" m.……4分
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241240093897583.jpg)
θ=37°,φ=90°-37°=53°……2分
tanφ=
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824124009405199.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824124009420190.gif)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824124009436259.gif)
h=
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824124009452275.gif)
略
![](http://thumb2018.1010pic.com/images/loading.gif)
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