Pascal's law

In the physical sciences, Pascal's law or Pascal's principle states that "a change in the pressure of an enclosed incompressible fluid is conveyed undiminished to every part of the fluid and to the surfaces of its container." [cite book
last = Bloomfield
first = Louis
title = How Things Work: The Physics of Everyday Life (Third Edition)
publisher = John Wiley & Sons
date = 2006
pages = 153
isbn = 047146886X ]

The difference of pressure due to a difference in elevation within a fluid column is given by:

:$Delta\; P\; =\; ho\; g\; (Delta\; h),$

where, using SI units,

:ΔP is the hydrostatic pressure (in pascals), or the difference in pressure at two points within a fluid column, due to the weight of the fluid;:ρ is the fluid density (in kilograms per cubic metre);:g is sea level acceleration due to Earth's gravity (in metres per second squared);:Δh is the height of fluid above (in metres), or the difference in elevation between the two points within the fluid column.

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.

Applications

ee also

*Pascal (unit)
*Fluid statics
*Pascal's contributions to the physical sciences

References