All Questions
Tagged with classical-mechanics thermodynamics
193
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Why the interaction between system and thermal bath does not affect the energy levels of the system?
When we write down the full Hamiltonian of a system in contact with a thermal bath, it is as follows:
$$H_{\text{total}} = H_{\text{system}} + H_{\text{system+bath}} + H_{\text{bath}}.$$
As our focus ...
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How work is done by rapid expansion or compression at adiabatic process?
In adiabatic processes, when a gas is compressed rapidly, the internal energy of the gas increases and work is done on the gas. Similarly in expansion the internal energy decreases and work is done by ...
CommunityBot
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Why exactly do we say $L = L(q, \dot{q})$ and $H = H(q, p)$?
In classical mechanics, we perform a Legendre transform to switch from $L(q, \dot{q})$ to $H(q, p)$. This has always been confusing to me, because we can always write $L$ in terms of $q$ and $p$ by ...
- 207k
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"Can Statements About Heat Transfer, Work, and Internal Energy Coexist in Thermodynamics?"
How can both the statements "For a closed system undergoing a cycle, net heat transfer is equal to net work transfer" and "According to the first law of thermodynamics, net heat less ...
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The correct formulation of temperature resistivity in Drude model
In this link the document uses $F = ma = qE$ to get drift velocity(Eq.9.6,page10), and then to resistivity(Eq.9.8,page10). But the document also said velocity due to temperature is magnitudes larger ...
- 419
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Calculating coefficient of performance (COP) for Heat Pump
Here I am considering the following cycle;
I know that the coefficient of performance for a heat pump can be calculated by;
$$COP=\frac{Q_h}{W}$$
Where $Q_h$ is the heat exhausted into the hot ...
CommunityBot
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What is the connection between energy in classical mechanics and thermodynamics
In classical mechanics the concept of energy is very simple. If I have a bunch of particles $r_1$...$r_n$. Then the total energy is:
$$E=\frac{1}{2}m(\dot r_1^2+...\dot r_n^2)+U(r_1...r_n)$$
Now in ...
- 12.1k
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Calculation of work done in different processes of thermodynamics in Physics and Chemistry
I am a high school student and I am very confused in thermodynamics, My confusion is that :In physics, when we study thermodynamics, we say that we cannot find the work done in irreversible processes ...
CommunityBot
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Are the magnitudes of the forces in activity in the two sides of a piston always the same?
This question has come to my mind when I was learning about pressure-volume work.
I was told that the pressures applied on both sides of a massless piston is always the same. So, since
F = P/A,
I have ...
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Solving thermodynamics with classical mechanics
I realized that enthalpy is defined as the total "energy content" of the system. Given that in Hamiltonian mechanics we also deal with the total energy H = T + V, can we somehow use ...
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How can I relate the temperature distribution in a solid with the mechanical stress due to thermal expansion? [closed]
How can I relate the Temperature distribution in a solid of simple geometry, like a cylinder, to the mechanical stress due to thermal expansion? I understand that using the linear expansion ...
- 26.4k
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What are the relations between different classical states of matter? [closed]
This may not a good quesiton I guess, but it is very confusing while I was studying the classical states of matter :- SOLIDS, ...
- 26.4k
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1
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Drawing a parallel between thermodynamic potentials and (mechanical) potential energy
Can we make an analogy, in the narrow sense, between potential (gravitational) energy and a thermodynamic potential (eg: free energy or Gibbs potential)? Specifically, if an object of mass $m$ is at ...
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What does the Work done by the system In First law of thermodynamics actually mean?
Does the work done in dQ=dU+dW include just the external work done by the system (on the atmosphere given by pdV), OR does it also include internal work done in a system--be it conservative or non-...
- 21
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Modeling of an ideal gas from a Classical Mechanics perspective
Say we have a box with a (large enough) side $L$ in which there is are $N$ indistinguishable particles, each having a speed $\vec{v}_i$. Let us also say these particles don't interact with eachother ...
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