If we know the size of the force (F) and the area over which the force is applied (A), then we can calculate pressure using


Here is the outline of a pupil’s shoe, it’s drawn on graph paper so that the area can be calculated quickly by counting the large squares.  Each large square is 1 square centimetre – we counted the approximate area by considering only whole squares inside the black outline of the shoe.

shoe outline

Assuming a mass of 50kg, the pressure when wearing these flat-soled shoes is

P={(50 x 9.8)N}/{(0.0306)m^2}=16000Nm^{-2}

The red shaded area of our photo shows the reduction in area when heels are worn.  With heeled shoes, the area is reduced to approximately 1 square cm per shoe.  The change in the pressure is staggering:

P={(50 x 9.8)N}/{(0.0002)m^2}=2450000Nm^{-2}

The Science Babe has made a video on this topic.

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