Question

When you walk normally, your front heel strikes the ground and there is a force on your foot from the ground which is a vector sum of normal force and friction force and is directed along your leg as shown. For a regular walk, your leg makes an angle of 30° from vertical and the normal force peaks at 1.1 times the body weight. For a person with a mass of 65 kg:

a) What is the magnitude of the normal force?

b) What is the magnitude of the friction force?

c) What is the minimum coefficient of static friction to not slip?

d) Explain why you might need take shorter than normal steps to not slip on an icy surface.

Answer 1