mass point

• 质点

mass point的用法和样例：

例句

1. A particle has no extent so that its position is a point.
   质点没有广度因此它的位置是一个点。
2. One instance of simple harmonic motion is that of the projection on any diametre of a point which describes a circular path with uniform angular velocity.
   当一质点以匀角速度作圆周运动时，则它在任意直径上的投影的运动便是简谐运动的一例。