posted by Josh on .
A person rappels down a cliff. The person uses a 0.5 inch diameter rope, creating a 170-lb internal force. What is the normal stress in the rope.
I got 340 by diving 170 from .5 is this right?
No. You have to divide the tension by the area of the rope's cross section, (pi/4)*(0.5)^2 = 0.196 in^2, NOT the diameter. The answer will be in pounds per square inch (psi), if you do.