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CD Hovercraft Name__________________

Can you make your own personal hovercraft?

What You Need

An old CD of any type, A thread spool or a stopper with a hole in it, Super Glue (or hot glue), Balloon

What You Do

1. Glue the spool with the opening in the spool over the opening in the CD. Let the glue dry completely.

2. Stretch the mouth of a balloon over the other end of the spool.

3. Blow up the balloon through the opening in the CD. You can put your finger over the opening to prevent the air from escaping.

4. Place the CD down on a flat smooth surface and let it go. You can give it a push to start it moving.

5. Try different size balloons to see which sizes work best. Have a friend build one and have races.

What’s Going On?

Have you ever played air hockey? In most Air Hockey games, the puck rides on a cushion of air. Your personal hovercraft is also riding on a cushion of air.

The force of the air escaping becomes equal to the weight of the hovercraft and allows the hovercraft to levitate. The hovercraft is lifted off the table and friction is greatly reduced. Friction is a contact force that opposes motion. Since the hovercraft has very little contact with the surface, there is very little friction. When you give it a push (a force), you cause it to accelerate.

Questions

1. Why does the hovercraft levitate? ______________________________________________________________________________________________________________________________________________

2. What forces are acting on the hovercraft before you push it?

_______________________ and __________________________________

3. When you gave the hovercraft a push, what happened? _______________________________________________________________________

4. Why does the hovercraft eventually quit moving?

5. What did a bigger balloon do?

______________________________________________________________________