Step 6: To Use
air flows out of the balloon, through the spool, and under the CD. Because the CD has a very flat surface and is evenly weighted, it lifts the entire hovercraft off the table. The air cushion between the CD and the table reduces the friction (a force that slows moving objects) and allows the Balloon Hovercraft to glide along the table. This is a similar principle to what allows air hockey pucks to float (although their air cushion comes up from the table).