# Thread: Thermodynamics & Stat. Mech.

1. ## Thermodynamics & Stat. Mech.

If anyone is good at Stat. Mech or Thermodynamics pls look at this and let me know where'd you start.

EDIT: Calling you out @Marksman Bryan.

2. ## Re: Thermodynamics & Stat. Mech.

I've seen this problem before... might be able to check my old thermo notes tomorrow. Too tired to think it through from scratch tonight.

3. ## Re: Thermodynamics & Stat. Mech.

Yay thanks! It's not due until Wednesday so just if you can help me out before then. I think it's a classic problem to show you that thermodynamic temperature can be negative(on Kelvin scale) in some cases cause a later question is "when would the temp be negative."

However, just reading this I'm baffled where to even start.

4. ## Re: Thermodynamics & Stat. Mech.

I haven't done stat mech or thermo in a few years so forgive me if I make a mistake.

First glance - N! divided by two other factorials makes me immediately think binomial distribution, and that fits the question of counting states (N choose R = N!/(R!*(N-R)!))
The delE/(2*mu*B) term in the answer combined with delE>>mu*B reminds me of a certain condition (approximation?) used in stat mech. can't remember the name - sorry. but if delE>>2*mu*B there's a derivative relationship I'd have to look up.

Total number of particles N = n1+n2

Rewrite equation for E in terms of n1 or n2 - solution makes me think it'd also be helpful to rewrite it as an equation for n1 or n2 (one or the other - I don't think you have to do both. could be wrong).

5. ## Re: Thermodynamics & Stat. Mech.

This is what I ended up going with.

6. ## Re: Thermodynamics & Stat. Mech.

I like how it says "by abusing algebra". Pity thermodynamics is not my cup of tea... no not at all, and this math is a little beyond me.

7. ## Re: Thermodynamics & Stat. Mech.

I try to make my homework sound dramatic. :3

EDIT: It's interesting to note here that this example can produce a negative absolute temperature if the first factorial term in the denominator is smaller than the second.

8. ## Re: Thermodynamics & Stat. Mech.

Looks right to me. Sorry I couldn't actually help, got stuck with my own Nuc Phys hw

9. ## Re: Thermodynamics & Stat. Mech.

Hi there,

New here, I've been searching for the Thermodynamics and Nuclear Physics handbook (from UNSW Canberra at ADFA). It's a previous year course and there's no access to the online resources already. What resources do you usually use for the Nuclear Physics assignments?
Corrupted reply field or something..

10. ## Re: Thermodynamics & Stat. Mech.

Heh, I'm surprised anyone bothered to reply to this thread and that I actually logged in in a somewhat timely fashion.

I don't have any great recommendations for standard Nuclear Physics undergrad. I don't think either course I took in it even had a required textbook. I did find Georgia State's hyperphysics website to be a very useful general resource and remember using it occasionally for Nuclear Physics.

Is this undergrad or graduate level? General overview course or something more specialized?

I ended up getting heavily into detectors and radiation effects on electronics, but only learned the general requirements for nuclear physics and reactors.

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