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 ...
- 1,068
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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 ...
- 137
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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 ...
- 29
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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 ...
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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, ...
- 35
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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 ...
- 1,571
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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-...
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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 ...
- 1,619
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How many degrees of freedom does a diatomic and triatomic molecule have at high temperatures?
I understand that a diatomic molecule has 3 translational and 2 rotational degrees of freedom. But since there is only 1 vibrational mode associated with a diatomic molecule and 1 vibrational mode is ...
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Is the equation for degrees of freedom $f=3N-k$ valid for all cases?
Consider the example of a linear triatomic molecule. Now at low temperatures, where we can exclude vibration, quite clearly degrees of freedom, $f=5$, with 3 translational and 2 rotational degrees of ...
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In statistical mechanics, why is one "allowed" to treat classical systems probabilistically?
Is the essential argument that these systems are microscopically chaotic enough that we can approximate their evolution as random (vastly simplifying calculations) and still make accurate experimental ...
- 161
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What would make the Legendre transformation interesting, from the graphical point of view?
The term "transformation" is often used in physics and mathematics for functions to denote a different (and useful) way of encoding the information in a function. In this question, I want to ...
- 2,599
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Why should this thermodynamics problem be indeterminate?
Callen asks us to consider the following
A cylinder of length $L$ and cross-sectional area $A$ is divided into two equal-volume chambers by a piston, held at the midpoint of the cylinder by a ...
- 1,095