Pascal’s Law


A fluid is a substance which occupies the shape of the container and transfer the pressure easily.

The word fluid includes liquids and gases because these two substances can flow.Gas (compressible) and Liquid (Incompressible) are fluid.

Pascal Law

Pascal’s law states that “pressure applied to a fluid in a closed container is transmitted equally to every point of the fluid and the walls of the container”

Pressure is the force acting per unit area. According to Pascal’s principle pressure applied to an enclosed fluid will be transmitted without any change to every point of the fluid and to the walls of the container. Important use of Pascal’s Law is force multiplier.

It can be explained with the help of the glass vessel filled with water and having holes over its surface. When a pressure is applied over the piston, the water comes out of the holes in the vessel with the same pressure. The force applied to the piston exerts some pressure on the water. This pressure is transmitted equally throughout the liquid in all directions. Pascal’s principle is used in daily applications of real life such as

  • Hydraulic press
  • Hydraulic jack
  • Hydraulic Brake
  • Hydraulic lift

Braking system

Hydraulic systems ( Braking system ) use an in-compressible fluid to transmit forces from one location to another.The braking system of vehicle work on pascal’s law. The hydraulic brakes apply equal pressure to be transmitted throughout the liquid. When the brake pedal is pushed, it applies a force on the master cylinder, which is transmitted equally through the liquid in the metal pipes to all the pistons of the other cylinders. The pistons in the cylinders move outward and press the brake pads. The force of friction between the brake pads and the brake drums stops the wheels.

Hydraulic Lift

In a hydraulic lift, a narrow cylinder (filled with in-compressible fluid oil) is connected with a wider cylinder and they are fitted with airtight pistons. According to pascal’s principle, applied pressure is transmitted to the piston of second cylinder.The piston of wider cylinder moves upward to lift the platform having a car or any other heavy object.

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