1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Thermodynamics of a Rubber Band

  1. Feb 7, 2014 #1
    1. The problem statement, all variables and given/known data
    For the rubber band model, calculate the fractional change in (L-L0) that results from an increase δT in temperature, at constant tension. Express the result in terms of the length and temperature.


    2. Relevant equations
    U=cL0T
    τ=bT((L-L0)/(L1-L0)); τ=tension, L1=elastic limit
    d/dL(1/T)=d/dU(-τ/T)


    3. The attempt at a solution
    I'm sort of at a loss on this one. I've tried subbing in all sorts of equations, but can't seem to make any real progress.
     
  2. jcsd
  3. Feb 11, 2014 #2

    rude man

    User Avatar
    Homework Helper
    Gold Member

    EDIT:

    By using Maxwell's 4th equation you can show that T dS = Cτ dT if τ is constant.

    You can also rewrite the 1st law as dU = T dS + τ dL.

    Just thinking - if we can assume an "ideal rubber band" analogously to an ideal gas, such that U is a function of T only, then dU = CL dT similar to dU = CV dT for an ideal gas.
     
    Last edited: Feb 11, 2014
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Thermodynamics of a Rubber Band
Loading...