Linear expansion of steel question

[ilyas415]

Homework Statement

The question i need help on is question 6 part (c). I think I need to use the equation:

2. Equations used:
\DeltaL = \alphaL\DeltaT

Linear expansion of steel: 12x10 K^-1 (\alpha)
Density of steel: 7800

3. My attempted solution:
I tried substituting in the values into the equation but the question did not mention anything about the length of the steel so now i am stuck for a solution. I tried using proportionality with density=mass/volume so density is proportional to 1/L. However I am not sure this if this is the correct way.

Thanks for your help in advance.

 

[Mapes]

That equation doesn't make dimensional sense; it has meters on the left but is dimensionless on the right. After that issue's fixed, you could try assuming a side length of 1 m, or 2 m. Does it make a difference?

 

[ilyas415]

ah, I've got it, assume it is a cube with edge length 1m, then I've got to substitute 1m into the equation to find the new length, then i use density = mass/volume, then i get the change in density