What made your ball bounce highest?
Here's how kids have voted so far:
28% drop it from higher up
39% swirl the water first
24% put more water in the cup
How's it work?
This Do It isn't well understand, but it seems that the ball bounces higher when it can receive more energy (kinetic energy) from the water. If the water is moving before you drop the cup, it has more kinetic energy to give to the ball, and the ball can bounce higher into the air. If the water is still when you drop the cup, it has less energy to give to the ball, and the ball does not bounce so high.
Want to talk about it? Go to the boards and discuss your results with other DFTVer's!