1. Atmospheric pressure decreases with altitude, or the height above of sea level. At higher altitudes, the density and temperature of the air are lower. As a result, the frequency of collisions of the molecules is decreased (lower). Hence, atmospheric pressure is lower.
Total pressure below the surface of a liquid.
1. The formula for liquid pressure, P = hpg, is used to determine the additional pressure due to the weightmof the liquid at any point below the liquid's surface.
2. As a result, the total pressure acting at a depth, h below the liquid's surface is the sum of the pressure due to the weight of the liquid (P) and the atmospheric pressure acting on the liquid's surface.
Total pressure acting on an object below a water with a depth of h = atmospheric pressure + hpg.
