The adiabatic tag has no wiki summary.
0
votes
0answers
39 views
How does the volume change affect an adiabatic process?
A gas consisting of rigid diatomic molecules was initially under standard conditions. Then the gas was compressed adiabatically, 5 times the original volume. Find the mean KE of rotating molecules ...
2
votes
1answer
36 views
Gas Laws And Adiabatic Process
Air at 20 degrees Celsius is compressed adiabatically from 1 bar to 10 bar, what will its temperature be?
With
$$P_1 = 1,$$ $$P_2 = 10$$
$$T_1 = 293K,$$ $$T_2 = unknown$$
using ...
1
vote
2answers
45 views
How is it possible to equate the internal energy at constant volume with the internal energy of an adiabatic process?
I hope my question makes sense. My problem is that, I have read through numerous textbooks that nC(cons. volume)dT = -PdV when deriving the relationship between T and V for an adiabatic process, ...
10
votes
3answers
229 views
The notion of an adiabatic process in thermodynamics -vs- quantum mechanics
I'm confused about the terminology in the two contexts since I can't figure out if they have a similar motivation. Afaik, the definitions state that quantum processes should be very slow to be called ...
2
votes
2answers
101 views
How is the energy/eigenvalue gap plot drawn for adiabatic quantum computation?
I was going through arXiv:quant-ph/0001106v1, the first paper by Farhi on adiabatic quantum computation.
Equation 2.24 says, $$\tilde{H}(s) = (1-s)H_B + sH_P$$ which means the adiabatic evolution ...
1
vote
2answers
66 views
What does it mean that an inspiral is 'adiabatic'?
Binary systems emit gravitational radiation. This causes the system to lose energy, which results in a shrinking of the semi-major axis. I have read on countless occasions that this 'inspiral' is ...
5
votes
1answer
180 views
Thermo homework (HW) problem
I do not believe this question can be solved with the thermodynamics knowledge that I have learned thus far, but someone correct me if I am wrong:
A 0.2-m³ tank containing helium at 15 bar and ...
0
votes
1answer
174 views
Adiabatic expansion of steam through a valve
I'm working on a homework problem, and I have a suspicion the textbook is trying to trick me.
The question is:
"Steam at 20 bar and 300 C is to be continuously expanded to 1 bar. Compute the ...
1
vote
1answer
176 views
Isentropic Processes
I'm having trouble understanding why reversible adiabatic processes are isentropic.
I understand that in a reversible adiabatic process there is no heat exchange and so $dQ = TdS = 0$. However, if ...
14
votes
1answer
319 views
If the ground states of interacting QFTs are so complicated, how did Nature find them?
My question was inspired by trying to understand the paper Quantum Algorithms for Quantum Field Theories, by Jordan, Lee, and Preskill. The main result of that paper is that scattering experiments in ...
1
vote
2answers
607 views
Adiabatic process of an ideal gas derivation
I am working through the derivation of an adiabatic process of an ideal gas $pV^{\gamma}$ and I can't see how to go from one step to the next. Here is my derivation so far which I understand:
...
4
votes
0answers
207 views
What is the Laughlin argument?
The fundamental question is
Why is Hall conductance quantized?
Let's start with the Hall bar, a 2D metal bar subject to a strong perpendicular magnetic field $B_0$. Let current $I$ flow in the ...
1
vote
1answer
374 views
Adiabatic expansion [closed]
I'll start off by saying this is homework, but I ask because I don't understand how the math should work (I don't just want an answer, I'd like an explanation if possible). I understand if this is ...
0
votes
1answer
1k views
Ideal gas law, pressure increase and temperature
If I had a container, full with air, and I suddenly decreased the volume of the container, forcing the air into a smaller volume, will it be considered as compression, will it result in an increase in ...
1
vote
2answers
246 views
Is it Possible to have Adiabatic Processes other than $PV^\gamma$ for the ideal Gas?
Is it possible to represent an adiabatic process for an ideal gas by a formula other than $PV^\gamma=Const$?:
Relevant Considerations:
We always need to connect a pair of arbitrary points/states ...
2
votes
1answer
202 views
Proof of adiabatic theorem on Wikipedia
I'm having trouble following the proof of the adiabatic theorem (apparently due to Messiah) on Wikipedia.
At one stage we have:
$U(t_1,t_0)=1+{1\over i}\int_{t_0}^{t_1}H(t)dt+{1\over ...
2
votes
1answer
131 views
Infinite quantum well width $L$ to $2L$ adiabatic process
If we change width of the infinite quantum well $L$ to $2L$ slowly enough, how it does change energy levels.
3
votes
1answer
114 views
Are energies non-transferable in the Born-Oppenheimer approximation, and when does it apply?
Adiabatic approximation or the Born-Oppenheimer approximation is used whenever the electronic motion is too fast that the electrons effectively see static nuclei and the nuclei, in turn, see an ...
1
vote
1answer
3k views
Why does a gas get hot when suddenly compressed? What is happening at the molecular level?
My guess is that the molecules of gas all have the same speed as before, but now there are much more collisions per unit area onto the thermometer, thus making the thermometer read a higher ...
12
votes
4answers
801 views
How slow is a reversible adiabatic expansion of an ideal gas?
A truly reversible thermodynamic process needs to be infinitesimally displaced from equilibrium at all times and therefore takes infinite time to complete. However, if I execute the process slowly, I ...
