点的复合运动定理推导的改进

Improvement on Point Compound Motion Theorem Deduction

在现行的工科理论力学教科书中，点的复合运动有三个定理，分别用不同方法推导。教改中我们改为用一套方法一次推出全部定理。不仅推导简捷紧凑，可以看到他们之间的联系；而且突出点对于不同参考系的速度、加速度之间的关系，物理概念更清楚。

In the present textbooks of theoretical mechaniacs,point compound motion comprises three theorems,which are respectively deduced in different ways. In the reform of our teaching,we adopt a compact way to deduce all the theorems once. So we not only see the connection between them but also stress the relation between the speed of the point in different reference frames and its acceleration, which makes the physical concept still clearer.