PRESSURE

The force due to the weight of a substance exerted over the area the substance occupies. In metric measure, it is the force acting on each square metre. To calculate pressure, divide the force (in newtons) by the area (in square metres). It is measured in newtons per square metre (N/m²). In Imperial (U.S.) measure, it is measured in pounds per square inch (lb/in.²) (psi). Also see atmospheric pressure , back pressure , boost pressure , center of pressure , clutch pressure plate , extreme pressure lubricant , mean effective pressure , oil-combination splash and pressure system , oil-full pressure system , oil pressure gauge , pressure bleeder , pressure cap , pressure radiator cap , pressure relief valve , safety pressure cap , and static pressure .