part 1

Bone has a Young’s modulus of about

1.8 × 1010 Pa . Under compression, it can

withstand a stress of about 1.58 × 108 Pa before breaking.

Assume that a femur (thigh bone) is 0.54 m

long, and calculate the amount of compression

this bone can withstand before breaking.

Answer in units of mm

part 2
How much pressure is applied to the ground
by a 79 kg man who is standing on square
stilts that measure 0.04 m on each edge?
Answer in units of Pa.
t 2