Fluid Mechanics

What is Pascal’s Law?

According to Pascal’s Law,

“The external static pressure applied on a confined liquid is distributed or transmitted evenly throughout the liquid in all directions”.

The static pressure acts at right angles to any surface in contact with the fluid. Pascal also found that the pressure at a point for a static fluid would be the same across all planes passing through that point in that fluid. Pascal’s law is also known as Pascal’s principle or principle of transmission of fluid-pressure. In 1653, Pascal law was stated by French mathematician Blaise Pascal.

Pascal Law Formula

Following is the formula of Pascal law:

P= F

      A

Where F is the force applied, P is the pressure transmitted, and A is the cross-sectional area.

Applications

Pressure applied at piston A is transmitted equally to piston B without diminishing the use of the fluid that cannot be compressed. Thus, piston B effectively serves as a platform to lift heavy objects like big machines or vehicles. A few more applications include a hydraulic jack and hydraulic press, and forced amplification is used in the braking system of most cars.

Hydrostatic pressure is defined as “The pressure exerted by a fluid at equilibrium at any point of time due to the force of gravity”. Hydrostatic pressure is proportional to the depth measured from the surface as the weight of the fluid increases when a downward force is applied.