Paper Ball Race With a Straw
Two crumpled paper balls, two straws and the edges of a tray table make a racetrack that fits in a train seat. Swapping a ball for a coin shows at once how much moving air can actually push.
What you need
- Two small pieces of paper
- Two drinking straws
- A coin
How to play
- Tear off two small pieces of paper and roll each one into a tight ball.
- Use the near and far edges of the tray table as the start and finish lines.
- Put both balls on the start line and give everyone a straw.
- Blow through the straws to push the balls to the finish without touching them.
- Race again with your straws further away and see how much harder it gets.
- Swap one paper ball for a coin and work out together why blowing no longer moves it.
