Impossible thermodynamics Q :(((

Thread starter RoisinCleary
Start date Apr 11, 2020
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Impossible Thermodynamics

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SUMMARY

The discussion centers on the implications of fixed volume in thermodynamics and its effect on work done on the surroundings or the system. It emphasizes the pressure-volume work equation, specifically W = -∫(V1 to V2) P dV, which illustrates that no work can be performed when the volume remains constant. Participants concluded that in a fixed volume scenario, the system cannot do work on the surroundings, nor can work be done on the system itself.

PREREQUISITES

Understanding of basic thermodynamic principles
Familiarity with the concept of work in physics
Knowledge of pressure-volume relationships
Proficiency in calculus, particularly integration

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This discussion is beneficial for physics students, thermodynamics researchers, and engineers involved in system design where volume constraints are critical.

Apr 11, 2020

RoisinCleary

Homework Statement: My professor has made up this question for us and I have no idea what I’m doing. I drew a diagram but I don’t know how to answer these questions

Consider a cylinder with a fixed piston, Half-way up the cylinder is a thin sheet of glass, separating the cylinder in to two halves.
N particles of gas exist on one side (A) of the partition, and 0(zero) particles on the other (B). At t=0, the glass plate shatters into tiny pieces (essentially ‘disappears’), & The gas in A can expand into side-B. a) is there any (moving) boundary for the gas to push against? Can any work be done? W=Integral(F * dX) b) what does the f(v) function of the gas as it passes by a plane close to the (shattered) glass plate look like (compare/contrast to the f(v) from side A before the glass broke.) c) in this ‘nearly instantaneous’ change, can heat flow from the cylinder into the gas? d) write out the numerical values of the terms in the 1st-law as a result of a)-c)

Any help is greatly appreciated :)

Relevant Equations: W=Integral(F * dX)

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Apr 11, 2020

etotheipi

If the volume of the container is fixed, can any work be done on the surroundings? Or on the flip side, on the system?

For thermodynamics it's often easier to consider the pressure-volume form for work done on the system, namely ##W = -\int_{V_1}^{V_2} P dV##.

Last edited by a moderator: Apr 11, 2020