谈“小球与均质自由杆的碰撞”中角动量守恒

Discussion on Conservation of Angular Momentum in Collision of a Particle and a Free Uniform Rod

对于光滑水平面上小球与均质自由杆的碰撞系统,选取碰撞时细杆的质心以及细杆和小球的质心作为两个不同的参考点,分别写出应用角动量守恒定律得到的结果,证明两个结果是等价的,因而系统对任意参考点的角动量都守恒。

It is concluded that the angular momentum of a particle and a free uniform rod with respect to arbitrary reference point is conserved in their collision on the frictionless horizontal.When choosing the center of mass of rod and the center of mass of rod-particle as two different reference points,the results of applying law of conservation of angular momentum are given.It is proved that the two results are equivalent.