Physics solids and fluids?

Question

For safety in climbing, a mountaineer uses a nylon rope that is 50 m long and 9.0 mm in diameter. When supporting a 80-kg climber, the rope elongates 1.8 m. Find its Young's modulus.

If you can help with this, I would greatly appreciate it because I do not understand it at all. Its a very new topic to me

Answer 1

Trillian is correct. Young's modulus is a measure of the "stiffness" of a substance. When an object made of the substance is subjected to a force, it experiences a stress - a force per unit area. It also experiences a strain - a stretch per unit length. Young's modulus is the stress divided by the strain. The larger the strain required to produce a given stress, the stiffer the material is. Note that Young's modulus is independent of the size and shape of the sample.

Answer 2

Use the following equation:

E = FL/(AdL)

where E is the Young's modulus, F is the applied force, which would be F = mg where m is the 80 Kg, and g = 9.81, L is the original length of the rope, A is the cross-sectional area ( that is pi*(D/2)^2 where D is the diameter and dL is the change in the length of the rope.