All Questions
31
questions
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3
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Why does adiabatic expansion occur in the Carnot cycle?
Several people have asked this question before and I haven't found any of the explanations even remotely satisfying.
To begin, Let's imagine our system consists of an ideal gas enclosed in a cylinder ...
0
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0
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135
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Effect of Uniform Motion on Internal Energy of an Ideal Gas in an Isolated container [duplicate]
“The internal energy of a gas contained in a beaker is U, if the box starts moving with velocity V, then internal energy of the gas will be...”
Elaboration
So, further explaining the situation, we ...
- 1
0
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3
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218
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Why can't entropy decrease for an adiabatic and closed system?
In equations (10) and (11) of this article by Curzon on the adiabatic piston, Curzon uses that a system which is thermally insulated cannot have its entropy decrease (irrespective of anything else ...
- 1,095
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2
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70
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Question regarding using $dU=nC_vdT$
In an Adiabatic process ,$Q=0$ (heat added or removed from the system is 0).
First law of thermodynamics states that ,
$dU=Q-W$...(1)
$Q=0$ .
Therefore $dU=-W$.
Now my question is why $dU=nC_vdT$ used ...
- 367
0
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2
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612
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Adiabatic process and internal energy
My question concerns the connection between change in internal energy $dE = Q - W$ and the available work in an adiabatic process.
My understanding is, that in an adiabatic process ($Q=0$) the change ...
2
votes
1
answer
590
views
Potential well expanding
Imagine you have a particle in a 1D potential well with infinitely high walls. Such a particle would have an energy of
\begin{equation*}
E_n = \frac{\hbar^2 \pi^2}{2m a^2}n^2
\end{equation*}
if the ...
- 23
3
votes
1
answer
2k
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Temperature change of an ideal gas during an adiabatic free expansion
During an adiabatic process there is no heat exchange and thus, q = o.
During a free expansion no work is done and so w = o.
Since q = U + w, thus we can say that during the overall process, change in ...
- 51
0
votes
2
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222
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Limits on Adiabatic Process
I am reading through the text "Advanced Engineering Thermodynamics" by Bejan that I found hereand have encountered a conceptual issue that I'm having trouble resolving on my own.
On page 64, ...
- 106
1
vote
4
answers
758
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On the meaning of $dU = \delta w$ for adiabatic processes
For an adiabatic transformation between state A and B $\delta q = 0$ and consequently from the first law of thermodynamics $dU = \delta w$, since $U$ is a state function its variation should be the ...
- 307
3
votes
1
answer
399
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How do we calculate the thermodynamic internal energy difference between two states?
So I've been doing a course in Thermodynamics for a while and one of the questions that occasionally struck me was "How do I practically calculate the difference of internal energy between two ...
- 773
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1
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21
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How can I make an engine by using adiabatic expansion?
In adiabatic expansion, gases expand when heating so volume and pressure also increase. How can I convert into work?
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1
vote
2
answers
2k
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What "adiabatic" means in context of photonic waveguides?
I only know the thermodynamic definition that "adiabatic process is a process that doesn't exchange the heat or mass with the surroundings".
Does it mean, that for example "adiabatic ...
- 3,034
1
vote
2
answers
315
views
Can the internal energy - work exchange take place in an isolated system
Isolated System is a system through which neither mass nor energy can pass. According to this definition, could it be implied that although we could have no energy exchange, we can exchange Internal ...
- 35
0
votes
2
answers
717
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Internal energy change in isothermal process vs. adiabatic process with $\gamma$ approaching 1
This might be a somewhat academic question (since there's no gas with $\gamma = 1$), but I am still interested in this.
Let's consider ideal gas and polytropic process with index $n$. We know, that ...
- 274
1
vote
4
answers
1k
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In adiabatic expansion does the internal energy of an ideal gas decrease?
By First Law of thermodynamic, for an ideal gas, if there isn’t heat transfer, work done by the gas is equal to decrease in internal energy of the gas.
Suppose that I have a perfectly-insulated ...
- 11