Air and water
There is a small and nice experiment that doesn't need much materials. We are going to talk about air and water here.
How does it work
It is simply air that is very important in this experiment. In the glass, there isn't only a piece of paper, there is also air!
When you plundge the glass vertically into the water, air is like a protection from the water to the piece of paper. Air even resist when you plundge it in the water (like a balloon in the water!). It's because air can only go back vertically to the surface, and therefore is stuck by the glass.
If you lean the glass, the air will come out, and bubbles will go up to the surface. Water will eventually take the place of the air in the glass, and wet the piece of paper.
Before the invention of diving suits, people used to use big sort of curved cover, and dive vertically. That way, they had a little stock of air inside the water!
- A bowl of water
- A glass
- A piece of paper
How to make this experiment
- Stick the piece of paper at the bottom of the glass by folding it. The piece of paper must stick to the bottom of the glass even when you turn it upside down.
- Turn the glass upside down and plundge it into the bowl of water vertically.
- Take it out vertically, and the piece of paper is still dry!