Problems and Solutions on Thermodynamics and Statistical Mechanics

102 Problems €4 Sdutioru on Thermodynam'cs €4 Statistical Mechanics

i.e.,

-Am,g + ZjelE = -m,g - lelE.

Am, - m,

(1 + z)lel '.

Hence E =

Qr GM r

(c) AS E= --, r2 r g = r2 r , we have

GMAm,-me GM Am,

Q/r2 = - M-

r2 (I+ .Z)lel r2 (I+ Z)lel.

GMAm,
Hence Q =
(1 + Z) 14.
(d) For hydrogen, one has A = 1, Z = 1, giving

GMm,

QW- 1.5 x lo3 oc.

214

1103
Consider a thermally isolated system consisting of two volumes, V
and 2V of an ideal gas separated by a thermally conducting and movable
partition.

Fig. 1.30

The temperatures and pressures are as shown. The partition is now allowed

to move without the gases mixing.

When equilibrium is established what is the change in the total internal

energy? The total entropy?

What is the equilibrium temperature? Pressure?

(SUN Y, Buffalo)