Recent content by Robert Davidson

Chet No problem. But thank you very much for clearing this one up for me. I confess to a tendency to try and identify general rules, or at least to try and get an in depth feeling for a rule. As usual, I really appreciate your time. Bob

Interesting. Is this unique to the isochoric process? The increase in entropy of the surroundings is due to less entropy transferred to the system, as opposed to the system ridding itself of the entropy generated by transferring it to the surroundings in the form of heat? Is it also unique to...

"To be even more straightforward about this, in the irreversible process, less entropy is transferred to the system from the surroundings" Yes, I calculated that. For the reversible process the entropy transferred to the system from the surroundings is $$\Delta...

Hmm. Could it be that since no work is done in the isochoric process, be it reversible or irreversible, then there is no impact of the entropy generated on work? Or, to put it another way, the only time entropy generation affects work is if it occurs in a process that produces work?

Consider a reversible ideal gas cycle consisting of: 1. An isochoric heat addition, 2. An isothermal expansion to the initial pressure, and 3. An isobaric compression to the initial volume. What, if any, is the difference in net work done by the gas in the cycle if the isochoric heat addition...

In short: Experience.

Wow. It took me a while, but I was able to follow your derivation. What I don't understand is how you determined all the mathematical manipulations that you needed (the "road map", so to speak) to demonstrate that dT/dS is negative. I couldn't have done it.

Oops! Sorry. Didn't look at it closely enough. Probably something like added red curve below.

OK. but which figure (1 or 2) applies? Your example started with an i Before I even try to follow this, I need to go back to your previous answer, that n is a constant for the entire process. I'm afraid I'm losing you (please be patient) and starting to feel stupid. Fig 4 below shows, as I...

Just so I understand correctly. See the figures below. Fig 1 shows what I originally thought you meant when you said "Another example is an isothermal expansion followed by an adiabatic expansion". You subsequently correctly surmised I was thinking you were talking about the expansion portion...

Just so I understand correctly. See the figures below. Fig 1 shows what I originally thought you meant when you said "Another example is an isothermal expansion followed by an adiabatic expansion". You subsequently correctly surmised I was thinking you were talking about the expansion portion...

I agree with you when you say "So what temperature could the guy mean?" I don't see how he can come up with the function T(S) for an irreversible process. Regarding your reference, I don't have (free) access to it, but statistical mechanics (statistical thermodynamics) is above my head. Never...

Got it. Thanks.

OK. So you still get an increase in entropy with the removal of a small amount of heat and slight lowering of temperature because of the cumulative increase in entropy prior to the reduction in heat, as long as the reduction in heat is not too great to turn the change in entropy negative. Kind...

Could you please explain what you mean by "as long as the temperature decrease did not offset the entropy increase". In terms of our other conversation, if we used a continuous sequence of reservoirs at decreasing temperature to bring the temperature of our body H from TH to (TH+TC)/2, wouldn't...