Experiment 38 from We Are Teachers - 75 Easy Science Experiments

38. Create a Balloon Rocket

You need a balloon, a straw, string, and tape. Thread the string through the straw, tape the balloon to the straw, inflate the balloon, and let it go. The escaping air pushes the balloon along the string, demonstrating Newton’s Third Law of motion: for every action, there is an equal and opposite reaction.