FHSST Physics/Pressure/Summary
< FHSST Physics  Pressure
Contents
Important Equations and Quantities[edit]

Non Si Units for pressure[edit]
PSI: PSI stands for pounds per square inch. One PSI is equal to 6,894.76 Pascals
Atm: Atm stands for Atmosphere. This is the atmospheric pressure at sea level. I atm is equal to 101,325 Pascals
Hydrostatic pressure (head pressure)[edit]
Hydrostatic pressure is the pressure due to the weight of a fluid.
where:
 ρ (rho) is the density of the fluid (i.e., the practical density of fresh water is 1000 kg/m3);
 g is the acceleration due to gravity (approximately 9.81 m/s2 on earth's surface);
 h is the height of the fluid column (in metres). Other units can be used if the rest of the units used in the equation are defined in a consistent way.
It is important to realize that air is a fluid. This equation can be used to find the pressure created by air. This also means that if we are trying to find the pressure of a liquid open to the atmosphere, we must add in the atmospheric pressure to the pressure of the liquid to find the total pressure.
Notes[edit]
1[edit]
Pressure is force divided by area, so in a sense it does have a direction as force has a direction. The term pseudovector is sometimes used for such quantities.