by STEM Scouts
This entertaining science experiment has a short material list and can be performed in just a few minutes. Once you’ve completed the demonstration, it may remind you of a classic tabletop game.
- An old compact disk (a CD or DVD)
- A push-pull bottle cap
- Tape (or hot glue)
- A standard-sized balloon (9-12”)
- Begin by placing the bottle cap over the hole in the center of the disk
- Tape or hot glue the cap and disk together, ensuring there are no gaps in the seal
- Push the cap closed, inflate the balloon and place the opening around the bottle cap.
- Once the inflated balloon is attached, pull the cap up. What happens next?
How Does It Work?
Reminiscent of an air hockey puck floating around the table, this miniature hovercraft works in a similar way. The balloon feeds air through the cap and evenly distributes it across the bottom of the disk. The escaping air creates a thin cushion beneath the disk, which reduces the friction between the disk and the table allowing it to freely move.
Make this into a full experiment by changing some of the variables. What happens when you use a different sized balloon? How about a smaller or larger disk? You can even try using helium as opposed to air. How do these changes affect the performance of the tabletop hovercraft?