-1
$\begingroup$

Q: Is temperature directly proportional to rate of fluctuation of pressure?

--->What I mean by Oscillation/Fluctuation of Pressure

From oscillation of pressure I mean constantly increasing and decreasing the pressure by a fixed amount.
For example imagine a room with a pressure of 50 pascal, if we first increase its pressure to 55 and then decrease the pressure to 45 that would be oscillating the pressure by 5 units back and forth

Suppose we do not add more molecules and our cube container is changing the shape. There are no sound-like longitudinal waves produced and everywhere pressure changes at the same time. ] Reason that made me ask this question: Because if temperature depends upon the KE of molecules and we oscillate the pressure we will just be shaking the molecules inside. So this should increase the temperature as well because the more you shake the more motion particles do.

Statement: [I know temperature is directly proportional to Pressure but is it also proportional to "the rate of oscillation" of pressure?]

Improve this question
$\endgroup$
3
  • 1
    $\begingroup$ Your example is inconsistent with the preceding statement as it involves oscillation of temperature, not pressure. Please clarify. $\endgroup$
    – Bob D
    Commented Jan 1 at 22:35
  • $\begingroup$ Considerably at which frequency? $\endgroup$
    – Ndamukunda Arnaud
    Commented Jan 1 at 23:07
  • 2
    $\begingroup$ It depends, are you increasing the pressure slow enough so that pressure is well defined and the same at all points inside the box, are you allowing for pressure waves, or turbulence? are you allowing heat exchange with the surroundings? etc $\endgroup$
    – Pato Galmarini
    Commented Jan 1 at 23:59

2 Answers 2

Reset to default
1
$\begingroup$

To simplify things, let the gas exhibit ideal gas behavior for the range in temperatures and pressures involved. Then we can apply the ideal gas equation of state and general gas equation for equilibrium:

$$PV=nRT$$

$$\frac{P_{1}V_{1}}{T_{1}}=\frac{P_{2}V_{2}}{T_{2}}$$

From oscillation of pressure I mean constantly increasing and decreasing the pressure by a fixed amount. For example imagine a room with a pressure of 50 pascal, if we first increase its temperature to 55 and then decrease the temperature to 45 that would be oscillating the temperature by 5 units back and forth

Your example is inconsistent with the preceding statement as it involves oscillation of temperature, not pressure. In any event, oscillations in pressure can create viscous friction in gases that, in turn, can increase the internal energy and temperature. This is the result of the generation of entropy in an irreversible (non-quasistatic) process.

Statement: [I know temperature is directly proportional to Pressure but is it also proportional to "the rate of oscillation" of pressure?]

For an ideal gas, temperature is directly proportional to pressure only under equilibrium conditions for a closed system where the volume is constant.

Hope this helps.

Improve this answer
$\endgroup$
0
$\begingroup$

When you increase the pressure it means that or you reduce the volume of the container or you added more molecules on the system, this means that will be more number of collisions between this molecules because there are less space between them so the temperature will rise up. When you add more volume the space between molecules will be greater so there will be less collisions decreasing the temperature. The only way to "shake" the molecules is making a variable magnetic field that goes through the molecules increasing their potential energy and rotating them increasing the heat (This only work for polar molecules). https://en.wikipedia.org/wiki/Kinetic_theory_of_gases

Improve this answer
$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.