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Balloon-Powered Car Project

Did you know? Newton’s third law of motion can be observed in sports. For example, in swimming the swimmer’s stroke pushes on the water and the water pushes back on the swimmer propelling him/her forward. In kicking a football, the foot pushes on the ball and the ball pushes on the foot in the opposite direction with the same amount of force.

What’s happening?

After you put the car on a surface and let go of the straw, the air moves out of the straw in one direction and the car moves in the opposite direction.

Sir Isaac Newton developed three laws of motion in 1665 when he was only 23 years old. These laws revolutionized how science explained movement by describing how the forces acting on an object are responsible for the object’s motion.

Your balloon powered car is a good example of Newton’s third law of motion. It states, “To every action there is an equal and opposite reaction.” This means that if object A pushes on object B, object B pushes back on object A with the same amount of force. In the case of the balloon-powered car, the air is pushed out of the straw in one direction and the car is pushed in the opposite direction.

Newton’s third law of motion is perhaps the most widely recognized and incorrectly used of the three laws. Despite occurring all around us, Newton’s third law can be difficult to comprehend. For example, if you lean against a wall it is easy to imagine that your shoulder is pushing, or exerting a force, on it. It is less easy to realize that not only is the wall pushing on your shoulder, but that it is pushing with an equal amount of force.