'''Pressure''' (symbol: P) is the [[force]] per unit area applied in a direction [http://en.wikipedia.org/wiki/Perpendicular perpendicular] to the surface of an object. [http://en.wikipedia.org/wiki/Gauge_pressure Gauge pressure] is the pressure [[relative]] to the local atmospheric or ambient pressure. | '''Pressure''' (symbol: P) is the [[force]] per unit area applied in a direction [http://en.wikipedia.org/wiki/Perpendicular perpendicular] to the surface of an object. [http://en.wikipedia.org/wiki/Gauge_pressure Gauge pressure] is the pressure [[relative]] to the local atmospheric or ambient pressure. |