PHY 4523 Spring 2000
Extra Credit Assignment
Due in my office by 5:00 pm on Wednesday, May 3.
Each problem is worth up to 1.5% of the total course score. To gain full credit you should
explain your reasoning and show all working. (This is particularly true for problems where
the final answer is given by Reif.) Please write neatly and include your name on the front
page of your answers.
1. Reif Problem 9.5. You may omit part (e).
2. Reif Problem 9.20.
Addition: (c) Derive an algebraic expression for the root-mean-square velocity vrms of
an ideal electron gas and evaluate your result for sodium. You may assume that the
velocity of each electron is v = h̄k/m where m is the mass of the electron and k is
its wavevector. The root-mean-squared velocity of a collection of N particles having
velocities vi , i = 1, . . . , N is
v
u
N
u1 X
vrms = t
|vi |2 .
N i=1
3. Reif Problem 9.23.
4. Reif Problem 10.2.
5. Reif Problem 10.3.
Final Exam
The final exam will be held on Tuesday, May 2 from 10:00 am to 12:00 noon in 1216 NPB.
You will need a calculator and a writing implement during the exam. You may also bring
your lecture notes, Reif and/or Callen.
The questions will focus on topics from the following list:
• Quantum statistics of ideal gases—Maxwell-Boltzmann, Planck, Bose-Einstein, and
Fermi-Dirac distributions.
• Ideal gases—microstates, density of states, partition function in the classical limit,
rotational and vibrational modes of diatomic gases.
• The photon gas—cavity radiation, black-body radiation.
• Ideal Fermi fluids—conduction electrons in metals.
• Lattice vibrations—normal modes of classical 1D chains, Einstein model, Debye model.
• Ferromagnetism—mean-field treatment of the Ising model.