Set-up: Rubber band modelled as an Ideal chain (polymer) with Nr (links) monomers pointing right, and Nl monomers pointing left each of length l.(adsbygoogle = window.adsbygoogle || []).push({});

Find expressions for the length of the band, its statistical weight (iI think that means the multiplicity?) and its entropy, in terms of Nr and Nl.

The length L is just, L = (Nr + Nl)l

Statistical Weight Ω(S(R))

Entropy is given by S(R) = k.ln (Ω(S(R)))

whereRis a vector representing the net displacement of the ends.

I'm not sure how to get the statistical weight. I know the general formula is

Ω(N, a) = (a + N -1) / a!(N-1)!, is a = l in my case?

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# Homework Help: Thermondynamics: Ideal Rubber Band

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