Help with proof of thermodynamics equation

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The discussion revolves around deriving the equations for a thermodynamic system involving a wire under tension. The key equations to consider are the Helmholtz free energy (F) and its relationship with temperature (T) and entropy (S). The confusion arises from the dual use of 'T' for both temperature and tension, which complicates the derivation. It is suggested to modify the differential equation for free energy to account for the work done by stretching the wire, while potentially ignoring the pressure-volume work (PdV). Clarifying these variables is essential for solving the problem effectively.
ksingh1990
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1. Homework Statement
Suppose a thermodynamic system consists of a wire of length L under a tension T show that:
(dF/dL)=T
and
(dF/dT)=-S
(both are partial derivatives)


2. Homework Equations
F=U-TS
H=U+PV
G=U+PV-TS
dU=TdS-pdV
dF=-SdT-pdV
dH=TdS+Vdp
dG=-SdT+Vdp
dQ=TdS
dW=pdV


I'm getting confused with the T for temperature and T for tension. Please explain to me how to do this as I have no idea about where I should begin.
Thank You
 
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How about modifying the differential equation dF=-S\,dT-P\,dV to incorporate work done by stretching the wire? Also, you can probably ignore P\,dV work in this problem.
 

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