The two thigh bones (femurs), each of cross sectional area `10cm^2` support the upper part of a human body of mass 40kg. Estimate the average pressure sustained by the femurs?

Explanation

Total cross sectional are of the femurs is `A=2 times 10^-4 m^2`. The force acting on them is F=40 kg wt =400n . This force is acting vertically down, and hence, normally on the femurs. That the average pressure is
`P_(av)=F/A=2 times 10^ N m^-2`