# Mechanical Principles, question on linear expansion of aluminium.

1. Jun 24, 2009

### RingwoodPye

1. The problem statement, all variables and given/known data
Question: If the linear expansivity of aluminium is 24 x 10-6 K-1, how much does the aluminium expand during the heating?

2. Relevant equations
As far as additional information on the question goes;
An aluminium rod is heated from 15 degrees Celsius to 120 degrees Celsius. The dimensions of the aluminium rod are 12mm (diameter) x 1.2m long. The density of aluminium is 2700 kg per meters cubed.

3. The attempt at a solution
So far I'm completely stumped, we may have covered it but I literally cannot work it out.

2. Jun 24, 2009

### Mapes

Hi RingwoodPye, welcome to PF.

The linear thermal expansion coefficient is the proportional increase in every (unconstrained) distance per degree temperature increase. That is, a value of 0 K-1 would mean no expansion, and a value of 1 K-1 would mean a 100% expansion per degree. Knowing this, can you calculate the new diameter and the new length?