Activity Determination of pressure water in a tank. Use the model tank to carry out this activity.

The pressure exerted by a fluid increases with its depth. This is given by the formula $P = \rho gh$, where $\rho$ is the density of the fluid, $g$ is the acceleration due to gravity, and $h$ is the depth from the surface of the fluid.

In your diagram, straw A is at the shallowest depth, straw B is at a medium depth, and straw C is at the greatest depth. Therefore, the water pressure will be lowest at A, medium at B, and highest at C.

If the container is filled with water and the straws are open, water will flow out horizontally from each straw.

• From straw A (shallowest), the water will flow out with the least force and travel the shortest horizontal distance before hitting the ground.
• From straw B (medium depth), the water will flow out with more force than A and travel a medium horizontal distance.
• From straw C (deepest), the water will flow out with the greatest force and travel the longest horizontal distance.

A diagram showing this would illustrate three streams of water emerging from the straws. The stream from C would be the most powerful and arc furthest away, followed by B, and then A, which would have the weakest flow and fall closest to the container.