Pressure is defined as the force thrust acting perpendicularly on a unit surface area. Pressure can be calculated from the formula below;

Pressure= ForceArea            i.e. P=FA

If force is measured in newtons (N) and area in square meters (m²), then the S.I. unit of pressure is newtons per squared meter (N/m²). Other units of pressure include pascal (Pa), millimeter of mercury (mmHg), atmosphere (atm).

Example: A box of weight 100N occupies an area of 4m²; calculate the pressure exerted by the box.

Solution

Weight= 100N, Area= 4m² and pressure, P= F/A

P= 100/4= 25N/m²