Hovercrafts are pretty cool. They use air to hover a couple of feet up and can travel over land, snow, and even water. Since air is all around us, with a couple of things from around the house you can wrangle that air into a small but functioning hovercraft!
- An old CD or DVD (make sure it’s one nobody wants to use anymore)
- A pop-top from a water bottle or soap bottle
- Duct tape
- A pushpin
- A balloon
- A hot glue gun
- Tear off two 2-inch square of duct tape. Use them to cover the hole in the CD from both sides so there’s no sticky stuff exposed.
- Using your pushpin, poke 6-8 holes through the tape around the edge of the CD hole. This will concentrate the air flowing through and help the CD hover.
- Using your hot glue gun, glue the pop-top cap over the hole. Make sure the seal is completely airtight by opening the cap once the glue is dry and blowing through it. Air should only be coming through the holes you poked in the tape. If it’s leaking out the edges of the cap, add a bit more glue.
- When the glue is all dry you’re ready to add your air! Blow up the balloon as big as you can get it but don’t tie it off. Make sure that the pop-top is closed and pull the neck of the balloon down over the top part of it.
- Your hovercraft is finished! Pop the cap open to get the air flowing and watch it float!
So how come the CD hovers instead of blasting straight up?
The CD hovers because the air coming through those holes you poked gets spread out into a cushion underneath the CD, pushing it up off whatever surface you put it on. This is partially due to a scientific principle called Bernoulli’s Principle, after scientist Daniel Bernoulli. It says that fast moving air has low air pressure and slowly moving air has high pressure. When you concentrate the flow of air through those tiny pushpin holes you raise the pressure and lower the speed to help it form that cushion rather than simply blasting the CD across the room (like when you let go of an untied balloon).
Experiment with different bases for your hovercraft. How does a paper plate work? A Frisbee? An old record album? If you want to kick it up a notch you can go online and find blueprints for a full-sized hoverchair you can ride! Just make sure you have an adult handy to help you build it!