动量守恒定律和能量守恒定律是历年来高考命题的重点、热点,是广大考生普遍感到棘手的难点之一.碰撞问题常涉及动量和能量守恒,因此是常选的运动模型。在碰撞中最常涉及的是弹性碰撞,本文就从“一动一静”、“两动”弹性正碰两模型来研究. The law of conservation of momentum and the law of conservation of energy are the focus and hotspots of the college entrance examination propositions over the years. It is one of the most difficult problems for the majority of candidates. The collision problem often involves the conservation of momentum and energy. Therefore, it is a constantly selected movement model. In the collision, the most commonly involved is the elastic collision. This paper studies the two models of “dynamic, static,” and “dynamic”.