Pascal’s law or the principle of transmission of fluid-pressure (also Pascal’s Principle) is a principle in fluid mechanics that states that pressure exerted anywhere in a confined incompressible fluid is transmitted equally in all directions throughout the fluid such that the pressure variations (initial differences) remain the same.The law was established by French mathematician Blaise Pascal.
This principle is stated mathematically as:
- is the hydrostatic pressure (given in pascals in the SI system), 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 meter in the SI system);
- g is acceleration due to gravity (normally using the sea level acceleration due to Earth’s gravity, in SI in metres per second squared);
- is the height of fluid above the point of measurement, or the difference in elevation between the two points within the fluid column (in metres in SI).