变质量系统力学方程析

Analyses of the Dynamical Epuation of the Variable Mass System

本文从牛顿定律出发,采用隔离法导出变质量系统的动力学方程。对该方程中的有关物理量(特别是主体和质元及其受力情况)作了进一步的分析,并通过两个实例阐明采用这里提出的方法能使易于混淆的物理图象变得清晰直观。

According to the Newton laws,the dynamical equation of the variable Mass system is deduced by means of the isolation method.The relevant quantities in the equation,es- pecially the main body and the mass elements and the applied forces on them,are anal- ysed in detail.By the discussion of two examples,it is shown that our method can make some physical pictures clear and vivid,which are easily misunderstood in study.