Make A Hovercraft

Physics | 20-40 minutes

In this activity, students will build their own mini hovercraft to take home and wow their friends!

Materials Needed

  • One plastic soda bottle cap per student

  • One used CD per student

  • Latex balloon

  • Thumbtacks

  • Glue guns

  • Glue sticks

Steps:

  1. Poke 5 holes in the bottle cap using the thumbtack.

  2. Have an adult create a continuous bead of hot glue on the edge of the bottle cap.

  3. Stick the bottle cap to the middle of the CD.

  4. Have the adult create a bead of glue around the edge of the bottle lid if required to create a good seal.

  5. Blow up the balloon without tying it.

  6. Twist the neck of the balloon to keep it from deflating and pull the balloon edge over the edge of the bottle cap.

  7. Still holding the balloon closed, place the CD on a flat surface and then release it.

Explanation:

When the balloon is attached to your hovercraft, the air starts to slowly leak out of the bottom. The air that escapes underneath creates a “cushion” of air underneath the cd.

The reason this hovercraft moves around so easily is because picking the hovercraft off of the table means there is a lot less friction between the bottom of the hovercraft and the table.

Friction is part of what keeps us from sliding around when we walk.

Have you ever slipped on a hard floor with socks on?

It’s easy to slip because there is not very much friction or “stickiness” between your sock and the floor.

Now think about walking on carpet in your socks… It’s much easier, right?

That is because there is a lot more friction between your sock and the carpet then there was between your sock and the hard floor.

Try it!

Take your balloon off and try pushing the hovercraft around. Does it move as easily?

What happens if you only blow up the balloon a little bit?

Does your hovercraft move easily on carpet? Gravel? Other surfaces?

Real World:

Real life hovercrafts are really cool! They slip and slide around on water, land, mud, and ice! Because they can work on a lot of surfaces, hovercrafts are used for a lot of different things. Hovercrafts are used to carry people for tours, they are used for transporting people and supplies, they are used for search and rescue missions, and a lot more.

This technology is also used in air hockey tables. There is a fan under the table surface that shoots air out of tiny holes in the top. This creates that same “cushion” of air that the hovercrafts used. That makes it easy for the puck to slide back and forth.