Units of Measurement/Pressure

Pressure is the force per unit area applied in the direction perpendicular to a surface. Mathematically, pressure is defined as


 * $$ P = \frac{dF}{dA} $$

where:
 * P is pressure
 * F is the component of force perpendicular to the surface
 * A is the area of the surface

When a force is constant over an area, the pressure acting on that area is simply


 * $$ P = \frac{F}{A} $$

It can be given the units of N.m-2. Pressure is a scalar quantity, thus it acts in all directions at any given point. In order for pressure to create a force, the pressure must be integrated over some area.