# Tensile Forces

1. Nov 9, 2008

### asleight

1. The problem statement, all variables and given/known data

A circular steel wire 1.91m long must stretch no more than 0.0024m when a tensile force of 450N is applied to each end of the wire.

What minimum diameter is required for the wire?

2. Relevant equations

$$p=\frac{F}{\Delta A}$$

3. The attempt at a solution

I can't seem to solve for this at all. I've tried applying a volume to this exercise:

$$A=V/l$$, where l is the length, then $$dA=\sqrt{dV/l-Vdl/l^2}$$...

$$p=\frac{F}{\Delta A}=\frac{F}{\sqrt{dV/l-Vdl/l^2}}$$. This didn't work, as far as I remember...

2. Nov 9, 2008

### LowlyPion

Perhaps you want to look at Young's Modulus for the wire?

http://hyperphysics.phy-astr.gsu.edu/hbase/permot3.html#c2

3. Nov 9, 2008

4. Nov 9, 2008

### asleight

I solved and got 2.1mm...

It's not correct.

5. Nov 9, 2008

### LowlyPion

It's not what I got either.

Maybe re-check your numbers?