《验证动量守恒定律》实验的改进

关键词 验证 动量守恒定律 实验改进 《The verification momentum guard Heng laws 》experiment of improvement Wang Fuang-xiang Abstract《verification the momentum guard Heng laws 》of experiment theoretically clear understand but at actual in operation income of experiment the data usually have with theories bigger discrepancy.Why will appear so of difference?How work° out this problem?The writer practice according to the teaching for several years and again and again thinking found out this experiment oneself existence of severity shortage and put forward improvement of method. Key wordsVerification The momentum guard Heng laws Experiment improvement 现行高中物理新课本（试验修订本· 必修）第一册中关于《验证动量守恒定律》的学生实验，仍沿袭原来各种版本的老教材，是用研究碰撞过程中动量守恒来验证动量守恒定律的。这个实验，只要求研究两小球正碰时的规律。可是使用的实验装置却是研究斜碰时的那套器材。那套器材是为做斜碰实验设计的，像教材上那样搬来做正碰实验（如图所1示），不仅不易调节，且误差较大。其主要原因有二 1 实验器材中两小球半径相同。要使两球发生对心正碰，必须调节螺钉使其顶端与水平槽末端在同一水平面上。但碰后入射小球m1在离开水平槽水平飞行2r距离的过程中，必然在竖直方向要下落一段距离，它就必定与螺钉上端碰撞。这是一个系统误差。螺钉调节得越准确，m1与它的碰撞越不可避免。 2 螺钉上端放小球m2的小凹槽不太规则，螺母中螺纹攻