Air Pressure and Water Bottle Experiment
Air Pressure and Water Bottle Experiment
What you need is water bottle with cap, something to put a hole in the side of the bottle. Push pin, scissors, soldering iron. Adult supervision is needed. A pan to catch the water.
Chapters
0:00 Intro to Kids Fun Science
0:05 What you need in the description
0:13 Hole is the bottle and bottle is full of water
0:17 Squeeze bottle and water comes out of the bottle and you increase pressure inside the bottle
0:28 Release cap to let water out of the bottle
0:34 Put cap back onto the bottle to stop the water
0:39 Squeeze bottle with straw hole to release water
0:53 Take cap off which allows water to come out.
When the cap is on air pressure prevents water from coming out. However when the cap is off, it is not air pressure that is pushing the water out because air pressure is at equilibrium at this point. When the cap is off gravity is allowed to push the water out without the interference of air pressure.
This can be very confusing for many clever children (and people), because as stated, there is an air pressure forcing on each inch of the bottle, so if the cap is off, there is "mostly" the same pressure forcing on top of the water and the same pressure forcing on the side hole ... so there is an equilibrium and nothing should happen (in terms of air pressure). What drives the water out of the bottle is the pressure of the water above the side hole, not the air pressure. So beware of such wrong information, that can seem to be right.