Newton’s Laws of Motion

—1. If a body be at rest, it will remain at rest; or if in motion, it will move uniformly in a straight line until acted upon by some force. 2. If a body be acted upon by several forces, it will obey each as though the others were nonexistent, and this, whether the body be at rest or in motion. 3. If a force act to change the state of a body with respect to rest or motion, the body will offer a resistance equal and directly opposed to the force. In other words, every action is opposed by an equal and opposite reaction.