What you need:
1 CD - a sports water bottle cap - strong glue - a balloon
What to do:
Record your observations:
- Glue the cap to the middle of the CD (over the hole). Make sure the cap is closed.
- Blow up the balloon and slip it over the cap.
- Place the hovercraft on a smooth surface and pop the cap
- Why did the hovercraft move?
- Will it move when there is no air in the balloon?
- Can you describe what is happening?
- What if the cap is only half opened?
- Can you think of any improvements?