Newton's equation of motion

例句：

1. 1. In classicalmechanics, Newton's law of action and reaction is a fundamental principle.
   在经典力学中，牛顿的作用与反作用定律是基本原理。
2. 2. The equations of motion describe the motion of objects under the influence of external forces.
   运动方程描述了物体在外力作用下的运动。
3. 3. Newton's laws of motion are used to explain the behavior of objects in motion.
   牛顿的运动定律用于解释物体在运动中的行为。