The last law of motion is Newton’s third law. It states that for every action, there is an equal but opposite reaction. This means that whenever one object exerts a force on another object, the other object exerts an equal and opposite force on the first object. There is always a pair of forces acting on two interacting objects.
Forces always come in pairs. These pairs are known as action-reaction force pairs. It is easy to identify two interacting objects and describing who is pushing on whom and in what direction. For example, consider the motion of an automobile. As the car moves forward the wheels spin backwards, and as the wheel spin backwards the road is pushed backwards. Consecutively, the road reacts pushing the wheels forward. |
