## PHYS 317 Reading Assignment #5

Read section 2.2 and 2.3 and answer the following questions by email, hardcopy, or web form before class Wednesday, September 10.

1. How many oscillators are there in an Einstein solid with 2000 atoms?

Each atom is really 3 oscillators, so there are 6000 oscillators. (And while we could study any number N of oscillators, only N's divisible by 3 are physically meaningful.)

2. What is the multiplicity for 3 oscillators with 4 units of energy?

Using q=4 and N=3 in equation (2.9) gives 6!/(4! 2!) = 5*6/2 = 15

3. What does the second law of thermodynamics mean in terms of multiplicity?

Essentially, if you prepare a system in a macrostate with a relatively low multiplicity, it will tend to move to a macrostate of relatively high multiplicity.

4. What is the fundamental assumption of statistical mechanics?

That all microstates (of an isolated system in thermal equilibrium) are equally likely.

5. Was there anything you had particular difficulty with in this reading? Is so, describe briefly.