What is the correct calculation for the Young's modulus using Hooke's Law?

[groom03]

[SOLVED] More hookes law question

Homework Statement

i can't get the equation to work out to the right answer of 110-130Gpa

Homework Equations

E=kL/A

k-1.45
L=2metres
A = 0.292cm

The Attempt at a Solution

i get 0.0099Gpa

 

[G01]

Can you please post the question and how you got your answer? How is anyone supposed to help you if we don't know your question or how you got to your answer?

 

[groom03]

Sorry.

I've got to work out the Youngs modulus of a meterial using the equation k=EA/L which rearrnged to E=kL/A i know k because its the gradient of a force extension graph i made, A is the x-sectional area of the wire and L is original length of the wire. wiki says the youngs modulus of copper 110-130 Giga Pascals but i get something stupid like 0.009Gpa.

 

[G01]

Hmm. I'm thinking there may be some unit problems here if your off by that much. What are the units you are using in your calculations, including your graph?

 

[groom03]

I did some working on it today and i think you're right, I'm using Newtons, millimetres and metres in the same equation, i converted all the units properly and I've got a more sensible answer now.

 

[G01]

I did some working on it today and i think you're right, I'm using Newtons, millimetres and metres in the same equation, i converted all the units properly and I've got a more sensible answer now.

Good to hear. Sometimes it always boils down to something simple like the units.

 

[groom03]

Thanks for your help

 

[G01]

Anytime.