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How to Make a Hovercraft With a Balloon & a Plate

Hovercrafts seem to defy the laws of gravity as they float above land and water. These amphibious vehicles are propelled by engines that produce compressed air that is trapped beneath the vehicle, providing it with a cushion of air. While they may seem exotic, the basic theory behind the air propulsion used to power these vehicles is fairly simple, and there are a number of different air-cushioned models that you can build at home.

Things You'll Need

Sturdy paper plates or disposable plastic plates
X-Acto Knife
Plastic straws
Duct tape
Pennies

Instructions

- 1
  Cut a straw in half and insert one end into a deflated balloon. Seal the join by wrapping several layers of duct tape around it and continue wrapping the straw down to where it meets the plate, or hovercraft. Check that it is air-tight by blowing into the straw and making sure the balloon will hold air. The balloon is the power source for your hovercraft.
- 2
  Mark the center of a plate with a pencil and make two one-half-inch cuts that bisect and are perpendicular to each other on that spot. Place the plate upside-down and insert the free end of the straw through the opening, making sure the straw does not extend past the depth of the plate. The hovercraft's ability to rise will be affected if the straw allows air to escape around the edges of the plate.
- 3
  Apply strips of duct tape where the inserted straw meets the hovercraft body to anchor it, close any air gaps left by the x-incision, and keep air from escaping. Hold the hovercraft up to a light to check for any areas that need extra taping.
- 4
  Take another straw and indent one end length-wise so it fits within the end of the straw on underside of the hovercraft. Push it in firmly and try exhaling into it to make sure that the combined straws have an air-tight seal.
- 5
  Hold the join of the balloon and the straw in one hand and blow into the connected straws on the other side of the hovercraft to begin filling the balloon. If you need to take a breath, pinch the taped join of the balloon and the straw to keep the air from escaping. When you've finished, continue holding the balloon closed with one hand and remove the extra straw from the bottom of the hovercraft with the other.
- 6
  Place the hovercraft down on a flat surface and release your grip on the neck of the balloon. As the balloon deflates, the area underneath the hovercraft will fill up with a cushion of air that will eventually lift it and cause it to move.

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