You will need:
- Long string
- Sticky tape
- Drinking straw
What to do:
- Cut a very long piece of string.
- Feed the string through the straw. It must move easily.
- Stretch the string across a room and tie its ends to suitable places, for example a door handle or a chair.
- Stick two pieces of tape to the straw.
- Blow up the balloon. Hold the neck and attach the balloon to the straw. The air must not escape.
- Let go of the balloon. It rushes along the thread at high speed.
The balloon produces a jet of air which drives the balloon forwards. It works the same way as jet engines on airplanes. These engines produce powerful jet of air that drives the airplane forwards.