Balloon Rocket

Build a balloon-powered rocket on a string to see force in action! You will learn how air pressure and thrust push the rocket forward in the opposite direction of the escaping air.

Materials

• balloon (1)
• plastic straw (1)
• string (10-15 feet)
• clear tape (2-3 pieces)
• heavy objects for anchors (2, such as chairs or tables)

Safety

• Adult supervision required for sharp objects.
• Do not wrap string around neck or limbs.
• Adult supervision required for children under 8.

Steps

1. Tie one end of the string to a big, heavy object like a chair or a table leg.
2. Thread the other end of the string through the plastic straw.
3. Tie the loose end of the string to another heavy object across the room, pulling it tight so the string makes a flat, straight line.
4. Blow up the balloon about halfway and pinch the end shut with your fingers so the air does not escape.
5. While holding the balloon closed, have a friend or grown-up tape the balloon to the straw.
6. Pull the balloon back to one end of the string and let go to launch your rocket!