Minimum Diameter for Steel Wire: Solve It Now

[asleight]

Homework Statement

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?

Homework Equations

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

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...

 

[LowlyPion]

Homework Statement

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?

Homework Equations

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

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...

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

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

 

[asleight]

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

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

Duh. -.- haha.

 

[asleight]

I solved and got 2.1mm...

It's not correct.

 

[LowlyPion]

I solved and got 2.1mm...

It's not correct.

It's not what I got either.

Maybe re-check your numbers?