【一道AP2012力学题AringofmassM,radiusR,androtationalinertiaMR2isinitiallyslidingonafrictionlesssurfaceatconstantvelocityu0totheright,asshownabove.Attimet=0itencountersasurfacewithcoefficientoffrictionμandb】

　　一道AP2012力学题

　　AringofmassM,radiusR,androtationalinertiaMR2isinitiallyslidingonafrictionlesssurfaceatconstantvelocityu0totheright,asshownabove.Attimet=0itencountersasurfacewithcoefficientoffrictionμandbeginsslidingandrotating.AftertravelingadistanceL,theringbeginsrollingwithoutsliding.ExpressallanswerstothefollowingintermsofM,R,u0,μ,andfundamentalconstants,asappropriate.

　　一个质量M,半径R,转动惯量为MR2（平方）的环开始在光滑水平面上以初速度V0向右滑动,t=0时刻进入滑动摩擦系数为μ的平面开始滑动同时滚动.经过L距离后环只滚动不滑动.

　　求：（1）线速度V与t关系式；（2）角速度w与t的关系式；（3）运动距离L所用时间；（4）L的大小.