Pascal's law

In the physical sciences, Pascal's law or Pascal's principle states that the fluid pressure at all points in a connected body of an incompressible fluid at rest, which are at the same absolute height, are the same, even if additional pressure is applied on the fluid at some place. On the other hand, the difference of pressure between two different heights h1 and h2 is given by:

where ρ (rho) is the density of the fluid, g the sea level acceleration due to Earth's gravity, and h1, h2 are elevations. The intuitive explanation of this formula is that the change in pressure between two elevations is due to the weight of the fluid between the elevations.

Note that the variation with height does not depend on any additional pressures. Therefore Pascal's law can be interpreted as saying that any change in pressure applied at any given point of the fluid is transmitted undiminished throughout the fluid.