Question about transient temperature and pressure for air flowing into a box

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SUMMARY

The discussion centers on the transient temperature and pressure dynamics of air flowing into a vacuum box connected to a room. The room measures 10 meters by 10 meters by 5 meters, while the box is 1 meter cubed and initially at absolute zero temperature and pressure. The consensus is that the temperature and pressure will asymptotically approach equilibrium over time, with the rate of change being a decreasing exponential. Additionally, if the box's walls were to disappear instantly, sound waves would propagate through the room until equilibrium is reached.

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  • Understanding of thermodynamics principles, specifically heat transfer and pressure dynamics.
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  • Knowledge of sound wave propagation in different mediums.
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Chiel555
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Hi all; i have some ( more) questions:

Imagine a room of 10 meters long, 10 meters wide and 5 meters high, filled with air

and a box of 1 by 1 by 1 meter, completely vacuum; the box is connected to the room and open so the air can flow freely from the room into the box;

both room and box are perfectly insulated on the outside so no heat and no air can escape

now suppose that de room starts with a certain temperature T and pressure P and the box with temperature 0 en pressure 0;

you would expect that in time the room and the box have the same temperature and after a time the same
pressure
what are those times ?; are they the same ?
 
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Chiel555 said:
... the box is connected to the room and open so the air can flow freely from the room into the box; ...
It will depend on how "free" your "flow freely" actually is. In theory, the time will be infinite, because the temperature and pressure will approach equality asymptotically, as a decreasing exponential rate.

If you change the question to having the walls of the small box disappear in an instant, then the room will be filled with sound waves for some time, as the depression wave fills the vacuum at the speed of sound, and echos between the diagonal corners of the room. The question will then be, how quiet is equilibrium?
 
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