The pressure of a liquid does not depend on the volume (amount) of the liquid, but the pressure does depend on the depth of the liquid. For example, the water pressure at one meter beneath the surface of a swimming pool is the same as the pressure at one meter beneath the surface of the Pacific Ocean. However, the water pressure one meter deep in the ocean is less than the water pressure 50 meters deep. Our bodies can’t handle the pressure of the deep sea; it would collapse our lungs. We can only explore the deep sea in pressurized submersibles. The deep sea animals that live there have special adaptations to handle the pressure.
If you were a builder of dams, think about what you would need to consider. The deeper the water is behind the dam, the more pressure there will be on the dam. You will have to build the dam according to the depth of the water behind it, regardless of the amount of water behind it.
This is because pressure equals force over area (P = F ÷ A), and the deeper you go, the greater the force of gravity.
