213碰撞问题对心碰撞一般碰撞动量守恒2211202101vmvmvmvm121020120221201021012121212121vvmmmmevmvmvmvmEk恢复系数201012vvvve1e121012012221202102112mmvmvmmvmmvmvmmv0kE特别地21mm102201vvvv02021vmm且02101vvv02021vmm且1021012vvvv2120210121mmvmvmvv22010212121vvmmmmEk完全非弹性碰撞题31一机枪质量为M放置于光滑水平面上机枪...