Pressure and Depth
Pressure is measured in newtons per square meters, N / m2; this is known as a pascal, Pa.
1 pascal = 1 Pa = 1 [ N / m2 ]
The force exerted is independent of the direction.
Now consider the pressure Ph at some depth h beneath the surface of a liquid:
Look at the forces on a column of the liquid -- that column has a cross section area A and a height of h.
Density Atmospheric and Gauge Pressure Return to ToC, Solids and Fluids at Rest (c) 2002, Doug Davis; all rights reserved