3.2.2 Nature of Liquid Pressure

The pressure caused by a liquid has the following characteristics:

  1. Pressure in liquid does not depends on
    1. the shape of the container.

      Eventhough the shape of the containers are different, the pressure at the bottom are still the same if the depth of water are the same.
    2. the size of the container.

      Eventhough the size of the two container are different, the pressure at the bottom are still the same if the depth of water are the same.
    3. the area of its surface.

      Eventhough the area of A and B are different, the pressure at the two areas are still the same if the depth of water are the same.

Pressure Increases with Depth

  1. The deeper the liquid, the faster the liquid spurts out.
  2. In conclusion, the pressure in a liquid increases with depth.

Pressure Depends on the Vertical Depth, But not the Length of Liquid Column.


Pressure at A = Pressure at B

All Points at the Same Level in a Liquid are at the Same Pressure


The level of the surface of a liquid in a container is always the same because for a given liquid, the pressure is always equal at the same level.

Pressure Does Not Depend on the Surface Area of the Object.


Pressure exerted on the small fish
= Pressure exerted on the big fish

Pressure Acts in All Direction


The pressure at any point of a liquid acts equally in all direction.