The femur is a bone in the leg whose minimum cross-sectional area is about 3.60 10-4 m2. A compressional force in excess of 6.90 104 N will fracture this bone.

Question

(a) Find the maximum stress that this bone can withstand.

(b) What is the strain that exists under a maximum-stress condition

Answer 1

(a) Stress = Force/Area
= 6.90 10^4/3.60 10^-4 m2
= ___ N/m^2 (or Pascals)

(b) You need Young's modulus (E) for bone material. You will have to look it up. It probably varies with type of bone and the person's age.

Strain = Stress/E

See http://www.engin.umich.edu/class/bme456/bonefunction/bonefunction.htm