The purpose of the demonstration is to show how water pressure increases with depth. You can also make some rough measurements to show an approximate relationship between depth and water pressure.

Pressure is force per unit area. At any point in a fluid, the pressure is the same in all directions. Water pressure at a given depth in an open container, such as a swimming pool, is shown by the equation: P = gh, where

• P is the water pressure
• g is the acceleration due to gravity
• h is the depth of the water at that point
• gh is g times h

Fill the beaker with water

Insert the corks in the side openings and place the cylinder on a stand. Fill the cylinder with water from the beaker.  If possible, have a student at-ready to add water in the top as the corks are pulled to maintain a constant head.

Position a catch tray to the side to catch the streams of water.

Pull the corks and observe how far the stream of water shots out from each hole.