- a cup
- a sponge
- a table tennis ball
- Put about an inch of water in the cup. Float the table tennis ball in the water.
- Hold the cup over the sponge a few inches, and drop it. The ball doesn't bounce out.
- Try dropping the cup from a bit higher. The ball still doesn't bounce out.
- Now swirl the cup, then drop it from the original height. The ball jumped out!
- How else can you get the ball to jump out of the cup?
What made your ball bounce highest?