Water Pressure on Bottom Exceeds Weight of Water

How can the water pressure on the bottom of a container exceed the weight of the water? It happens because water pushes in all directions, including up as well as down.

In an upside-down T-shaped container, if you compress two springs and put them in the "T" parts in the bottom, the force of the springs on the bottom can far exceed the weight of the springs, because they are pressing against the horizontal surfaces of the legs of the "T".

This is exactly what happens when you put water in the container. The water is pushing up as well as down. The total NET force of the water is exactly the weight of the water, but this force consists of a large force on the bottom and a smaller force pushing upward on the horizontal surfaces inside the container.

That's why the force on the bottom (alone) can exceed the weight of the water. This large force is mostly canceled by the upward force of the water elsewhere in the container.

For a longer version of this presentation, see    • Water Pressure Depends Only on Depth, Not ...