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SEP115B: TUTORIAL 5
1. A 70 kg mountain climber dangling in a crevasse stretches a 50 m long, 1.0 cm diameter rope by 8.0 cm.
What is Young’s modulus for the rope?
2. Two stretched cables both experience the same stress. The first cable has a radius of 3.9×10-3 m and is
subjected to a stretching force of 450 N. The radius of the second cable is 5.1×10 -3 m. Determine the
stretching force acting on the second cable.
3. The femur is a bone in the leg whose minimum cross-sectional area is about 4.0 x 10-4 m2 . A compressional
force in excess of 6.8 x 104 N will fracture this bone.
(a) Find the maximum stress that this bone can withstand.
(b) What is the strain that exists under a maximum-stress condition?
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