Question

The two thigh bones(femurs),each of cross section area 10^2 supports the upper part of human body of mass 40kg . what is the average pressure sustained by the femurs is

Answer 1

area = 10 ^2
mass = 40
g=10

Pressure = force/area
= 10^2 × 40 ×10 (g=10)
= 4 × 10^2
pressure on each femur
= 4× 10 ^2÷2
= 2 × 10^2

Answer 2

The average pressure is 392 Kilo-Pascal

Given:

The femur bone or the thigh bone carries the mass of the body of 40 kg.  

Solution:

The pressure sustained by the femurs is dependent upon the weight and its area of cross section.  

Area of cross section of both femur $=2 \times 10^{2} \ m$

The force is weight of the body which is given below:

$F=m \times g$

$\Rightarrow F=40 \times 9.8$

$F=392 \ N$

Therefore,

$Pressure =\frac{\text { Force }}{\text { Area }}$

$P=\frac{392}{2 \times 10^{-2}}$

$P = 19600$

$P = 19.6 \ Kilo-Pascal$