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/|acceleration]] due to gravity.

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