质点组动量守恒中的速度问题

The Velocity Question for Particle System Momentum Conservation

利用动量守恒定律分析质点组问题时,必需注意质点组各质点速度的空间统一性和时间统一性。

It's necessary to pay attention to the unity of time and space for each particle velocity,when analysing the question for particle system use mom entum conservation law.