One idea for a Newton scooter project involves taping an inflated balloon to a homemade scooter with the open end in the direction of the wheelbase. Upon letting go of the balloon, the scooter moves in the opposite direction of the air. Using different types of balloons yields different results.
Newton's third law of motion states that for every force, there is a reactive force that is equal in magnitude and opposite in direction. A Newton scooter with a balloon attached demonstrates this law because it shows that the scooter propels in the opposite direction of the expelled air. This result means there was a reactive force acting on the scooter in response to the force of the air.
Students can try the Newton scooter project with different types of balloons to demonstrate the effect of balloon shape and size on the distance the scooter travels. Large, tubular balloons tend to create a larger displacement than small and round balloons. Large balloons hold more air, creating a larger thrust. Round balloons have a greater surface area that comes into contact with the incoming air from the reactive force. Therefore, the balloon uses up more energy pushing against the air, resulting in less available energy to move the scooter.