Problems and Solutions on Thermodynamics and Statistical Mechanics

(Ann) #1
Thermod pmics 81

we obtain
a2E a2E a2s - a2s
axaT aTaxl axaT aTax

From __ -- -


a2E
aTax

Thus (aE/a+ = t - T(at/aT),.
Substituting the expression for t, we have (aE/az)T = 0. It follows
that (ac,/az), = 0. Integrating, we get


E(z, T) = E(T) = 6 dE + E(To) = [ gdT + E(To)


= Lr KdT + E(To) = K(T - To) + E(To).


From
dS= %dT+T 1 [(a,),-t]dz aE
T

we find after integration

S(z, 2') = K In T - A - + - + const.
(;l: :)

(b) For an adiabatic process dS = 0 so that


After integration we have

= 0.292AZo ,


Hence fi = TO exp(0.292Alo/K).

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