You will need
An old CD or DVD disc
A 9” balloon
A pop-top cap from a liquid soap bottle or a water bottle
A hot glue gu
What to do
If you are using the cap from a water bottle, cover the center hole of the CD with a piece of tape and poke about 6 holes in the tape with a push-pin or small nail. This will slow down the flow of air and allow your hovercraft to hover longer.
Use the hot glue gun to glue the cap to the center of the CD or DVD disc. Create a good seal to keep air from escaping.
Blow up the balloon all the way and pinch the neck of it. (Don’t tie it.)
Make sure the pop-top is closed and fit the neck of the balloon over the pop-up portion of the cap. (This is usually easier with 2 people)
That’s it! When your ready to commence hovering, simply put the craft on a smooth surface and pop the top open.
How does it work?
The air flow created by the balloon causes a cushion of moving air between the disc and the surface. This lifts the CD and reduces the friction which allows the disc to hover freely. Large scale hovercraft are capable of traveling over land, snow and water.
Make it an experiment
The project above is a DEMONSTRATION. To make it a true experiment, you can try to answer these questions:
1. Does the size of the balloon affect the CDs ability to hover?
2. Does a helium balloon work better than an air filled balloon?
3. Do larger discs make better hovercrafts (plastic picnic plates, old record albums) ?