Pressure

Pressure in solids

Pressure is the force acting per unit area:

$$p = \frac{F}{A}$$

measured in pascals (Pa), where $1\ \text{Pa} = 1\ \text{N/m}^2$. A small area concentrates the force, giving a high pressure (e.g. a sharp knife, a drawing pin); a large area spreads the force (e.g. snowshoes, wide tractor tyres).