By Gina Napoli
Art by Scott Goto
What You'll Need:
- heavy-duty 6-inch-wide paper plate
- pencil or pen
What to Do:
- Use the pencil or pen to punch a hole about as wide as your pointing finger down through the center of the paper plate.
- Turn the plate upside down and push the mouth of the balloon through the hole.
- Blow up the balloon and hold it by the neck to keep the air inside.
- Place the hovercraft on a smooth, flat surface. Let go of the balloon and tap the side of the plate
to make the hovercraft glide.
How It Works:
As air flows downward and out of the balloon, it builds up air pressure under the paper plate. That air pressure lifts the whole hovercraft off the flat surface as air begins to escape evenly all around the edge of the plate. It floats on a cushion of air.
Based on this idea, a large hovercraft uses propellers to create a big cushion of air so that the craft can move across flat ground and even across water.