Saturday, 6 June 2009

A bottle with a hole

In order to make our experiment, we only need a bottle of water with it’s cap.

We make a small hole in a plastic bottle, about a half of its height, and we fill it full of water, while we are covering the hole.

If we remove our finger from the hole, no water comes out, but if we remove the cap of the bottle, the water starts to come out. But why?

If the cap is put, the internal pressure on the hole is equal to the external pressure and that’s why the water doesn’t come out of the hole.

But, if we remove the cap, we allow that the air comes into the top of the bottles, breaking the previous balance. The internal pressure on the hole is greater than the external pressure, so the water comes out of the bottle.

by Irene and Rafael


Alicia said...

Wow! This experiment is incredible! Congratulations!!

Claudia Cziprok said...

Congratulations for Irene and Rafael, this experiment is really magic! The balance of pressures is so surprising.. I liked very much. Undoubtedly, everybody will try it!

abd_30_6 said...

Thank You!