Calculating Length Change of Heated Copper Rod

[Dantheman1]

Homework Statement

A copper rod is 40.0cm long at 22.0 Celsius. If the rod is heated to 100.0 Celsius, what is it's increase in length.

Homework Equations

Linear expansion of copper is 16.8*10^-6

The Attempt at a Solution

Change in Length= (length)(change in temp.)(α)
So...
(40.0)(78.0)(16.8*10^-6)
=0.052 cm is the change in length?

Please let me know if/what I did wrong here.

 

[Hypersphere]

What answer are you expecting?

 

[Dantheman1]

What answer are you expecting?

Don't know, I acctually may have not got it wrong i just wanted to make sure.

 

[Hypersphere]

Don't know, I acctually may have not got it wrong i just wanted to make sure.

OK. Well, if it makes you feel better, those values (assuming you give α in the usual units) and the linear expansion formula does give me the same answer. Basically, thermal expansion is a small effect, which thus mainly matters for larger things.