1) First we filled up our cup of water to the very top.
2) Then we placed a piece of cardboard on the top and pushed out any air bubbles.
3) Now we took our hand away from the card and the water stayed in the cup.
4) It is a good thing the water stayed in the cup or I would be soaked!!!! hahaha
Why did this happen?? The water stayed in the cup because the air pressure has force or strength to overcome gravity. The air pressure pushes against the cardboard and stops the water flowing out.
By Alex, Harvey and Stevie