Homework #2 Due Tuesday Sept. 13

1. Kittel p. 25 #1

2. Kittel p. 25 #2

3. Kittel p. 25 #3 I am not happy with Kittel's
designation "non-equilibrium state" for states with *n* not equal
to zero. Mostly this is because the equilibrium state in the presence
of the field does certainly have a non-zero expected value of *n*.
So I would replace his term by the alternate term "constrained state."
You may use the fact that *W(n)=2 ^{N} w(n)* and use Eq. 6.8
for

4. Kittel p. 25 #4