Mathematical Example: Pressure

Question: The mass of a woman wearing a shoe is 50kg. The area of the bottom of the shoe is 200 cm². Find the pressure.

Given, mass, m = 50kg

force, F = w = mg = 50 kg x 9.8 ms^-2 = 490N

Area of the bottom of the shoe, A = 200 cm² = 200 x 10^-4 m²

We know, Pressure, P = F/A = W/A

Then, [490 N / 200 x 10^-4 m²]

= 2.45 x 10⁴ Pa

Note: If we divide the unit of force by the unit of area, we get the unit of pressure. Therefore the unit of pressure is Nm^-2. It is called pascal (Pa).

1 Pa = 1 Nm^-2

If a force of 1 N force is applied perpendicularly to an area of lin2 then the pressure generated is known as 1 Pa.