(adsbygoogle = window.adsbygoogle || []).push({}); First part of the question:

A high speed lifting mechanism supportsa 711kg object with a steel cable 24.9m long and 3.83cm(squared) in cross sectional area. Determine elongation of the cable.

I think I got this first part right... can anyone confirm my approach.

stress = F/A

F = mg = 711*9.8

A = .0383

strain = stress/Y

and then

elongation delta L = Lo * strain

Is this how you find elongation?

Second part of the question

By what additional amount does the cable increase in length if the object is accelerated upward at a rate of 3.3m/s2?

This was my approach to the second part. not sure if this is correct...

stress = F/A

but this time F = ma - mg (is this correct?)

everything else will be the same as the first part.

can someone please verify both these please.

Thanks in advance

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Stress/strain/elongation question

**Physics Forums | Science Articles, Homework Help, Discussion**