What is the Pascal's law?

Asked by: Anshuman Mathur


When you squeeze one end of a tube of toothpaste out the other end, you are watching Pascal's principle in action. The principle was first stated clearly in 1652 by Blaise Pascal (for who the unit of pressure is named):

A change in the pressure applied to an enclosed incompressible fluid is transmitted undiminished to every portion of the fluid to the walls of its container.

Pascal's principle put more simply, basically means that an incompressible fluid transmits pressure. This is the basis to hydraulic lever. In a hydraulic lever, for example, you apply a force to the left-hand piston over a given area, this force is then transformed in to a pressure which is transmitted through the hydraulic fluid or oil. This pressure then transforms back in to an output force over another given area for the right-hand piston.
Answered by: Dan Summons, Physics Undergrad Student, UOS, Souhampton