Newton’s Third Law of Motion states that for every action, there is an equal and opposite reaction. This means that when one object exerts a force on another object, the second object also exerts an equal and opposite force on the first object. These two forces are referred to as a force pair. A force pair identifies two interacting objects and describes the direction of the force acting on each object. It is important to note that both forces in the force pair are the same type (e.g. gravitational), are equal in magnitude, and are opposite in direction.
You can use a balloon to provide a simple analogy of how a rocket engine works. The air trapped inside the balloon is pushed out of the open end of the balloon. According to Newton’s Third Law of motion, the expelled air exerts an equal force in the opposite direction of the motion of the air, causing the balloon to move forward.
Hop into your student shoes as you learn how to construct and operate your rocket racer.