- String, like yarn
- Non-bendy straw
- Two poles that are a good distance away from each other - roughly 15 to 25 feet apart
- Tie a piece of string to one pole
- String the straw onto the string
- Tie the other end of the string to another pole
- Have the straw on one end of the string
- Inflate the balloon
- Twist the mouth of the balloon
- Tape the balloon onto the straw so is mouth of the balloon is facing the closest pole
- Balloons are made of an elastic material, when you blow into the balloon the material expands.
- When the mouth of the balloon is held (or tied) closed, the air has nowhere to go, so it pushes back to retain the balloon's shape.
- When the mouth of the balloon is open, the air has somewhere to go. The air pushes out the mouth of the balloon. Since the air is now moving, the rocket balloon also moves.
- This follows both Newton's Third Law of Motion- "for every action there's an equal and opposite reaction".