题目内容
如图所示,在圆锥形内部有三根固定的光滑细杆, A、B、C为圆锥底部同一圆周上的三个点,三杆Aa、bB、cC与水平底面的夹角分别为60o、45o、30o。每根杆上都套着一个小滑环(图中未画出),三个滑环分别从a、b、c处由静止释放(忽略阻力),用tl、t2、t3依次表示各滑环到达A、B、C所用的时间,则
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250015296663879.jpg)
A.tl>t2>t3 B.t1 <t2< t3 C.tl=t3<t2 D.t1=t3> t2
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250015296663879.jpg)
A.tl>t2>t3 B.t1 <t2< t3 C.tl=t3<t2 D.t1=t3> t2
D
试题分析:由牛顿第二定律可知滑环在杆上做初速度为0,加速度
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001529697566.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001529712260.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001529728845.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001529712260.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001529775981.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250015297901071.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001529806649.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001529837625.png)
![](http://thumb2018.1010pic.com/images/loading.gif)
练习册系列答案
相关题目