## pressureThe force acting normally on (at right angles to) a unit area of surface, or the ratio of force to area. The SI unit of pressure is the pascal (Pa = newton/meter ^{2}) but several other pressure units, including
the atmosphere (101.325 kPa), the bar
(100 kPa), and the millimeter of mercury (mmHg = 133.322 Pa), are in common
use. If a weight of 20 newtons (N) acts at right angles to on an area of 2 m ^{2},
the pressure it exerts is calculated as follows: According to the kinetic theory of gases, the pressure in a closed container of gas arises from the bombardment of the container walls by the molecules: it is proportional to the temperature and inversely proportional to the volume of the gas. ## Related category• CLASSICAL MECHANICS | ||||||

Home • About • Copyright © The Worlds of David Darling • Encyclopedia of Alternative Energy • Contact |