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.