PlanetPhysics/Hydrostatic Pressure

By the hydrostatic pressure $$p$$ inside a liquid at a certain point is meant the force $$F$$ acted by the liquid perpendicularly on a test surface in the point divided by the area $$A$$ of the test surface: $$p := \frac{F}{A}$$


 * The hydrostatic pressure is independent on the direction of the test surface.
 * The hydrostatic pressure does not depend on the form of the vessel containing the fluid.
 * The total force caused by the hydrostatic pressure on a horizontal area $$A$$ is same as the weight of the liquid column, which has the bottom $$A$$ and the height equal to the vertical distance $$h$$ of $$A$$ from the free surface of the liquid.\, This is the hydrostatic paradox .\,Thus, $$p = \frac{\varrho Ah\cdot g}{A} = \varrho hg,$$ where $$\varrho$$ is the density of the liquid and $$g$$ the acceleration due to gravity.

The above laws have been discovered and experimentally proved by Simon Stevin (1548--1620).