Question

Assume Young’s modulus of bone is 1.50 x 10^10N/m2. The bone breaks if stress greater than 1.50 x 10^8 N/m2 is imposed on it. (a) What is the maximum force that can be exerted on the femur bone in the leg if it has a minimum effective diameter of 2.50 cm? (b) If this much force is applied compressively, by how much does the 25.0 cm long bone shorten?

Answer 1

(a) Force = Stress × area

$$Force=1.5×10^8×3.14×(1.25)^2×0.000125$$

Force =73600 N

(b)

Strain = Stress/Y

Y is young's modulus

Let X be the change in the length

$X/L=1.5×10^8/15×10^9$

$X=0.25cm$