Pressure

Atmospheric pressure is the pressure exerted by the weight of Earth's atmosphere above us. At sea level it equals about 101 325 Pa (1 atm).

Gas pressure results from particles colliding with the walls of a container. Pressure increases when the temperature rises or when the volume decreases. Boyle's Law states that for a fixed mass of gas at constant temperature, pressure and volume are inversely proportional.

Hydrostatic pressure is the pressure exerted by a fluid at rest due to the weight of fluid above it. It increases with depth.

Definition of pressure, how area affects pressure, and the formula P = F/A.