Work done through linear expansion

Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
2 replies · 5K views
LadyMario
Messages
27
Reaction score
0
An 8000kg aluminum flagpole 100m long is heated by the sun from a temperature of 10°C to 20°C. Find the work done (in J) by the aluminum if the linear expansion coefficient is 24*10-6 /°C. (The density of aluminum is 2.7*103 kg/m3 and 1 atm = 1.0*105 N/m2)

I know w=PΔV, and I know V at 10°C = mass/density= 8000/2.7*103 = 2.963m3

I know how much longer the flagpole grows: ΔL=αLΔT = 24*10-6(100)(20-10)=0.024m

But how does the volume at 20°C relate to the growth of the flagpole through linear expansion?

The answer is suppsoed to be 213 J.
 
Physics news on Phys.org
Do you know the formula for volume expansion? The coefficient of volume expansion has a simple relation to the coefficient of linear expansion.
 
TSny said:
Do you know the formula for volume expansion? The coefficient of volume expansion has a simple relation to the coefficient of linear expansion.

Yea I found it in the textbook. We were never taught it in class, so I was trying to find another way to do it, but oh well :P