Timeline for Rigorous derivation of the mean free path in a gas
Current License: CC BY-SA 4.0
14 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Oct 14, 2022 at 10:53 | comment | added | Riemann | I also asked this here: physics.stackexchange.com/questions/731953/… | |
| Sep 30, 2022 at 12:06 | comment | added | Riemann | Also noting that $\langle v_r\rangle=\int_0^{\infty}\langle (v_r)_1\rangle P(v_1)dv_1$. | |
| Sep 30, 2022 at 12:04 | comment | added | Riemann | I am concerned about the last step. If I am correct, you use that $l=\frac{\langle v\rangle}{n\sigma\cdot\langle v_r\rangle}$. However, shouldn't one first calculate the mean path length for particles with speed $v_1$, and then average over all speeds $v_1$? If I am correct, the mean path length for particles with speed $v_1$ is $\frac{v_1}{n\sigma\cdot\langle (v_r)_1\rangle}$. Averaging this over $v_1$ would give $l=\int_0^{\infty}\frac{v_1}{n\sigma\langle(v_r)_1\rangle}P(v_1)dv_1$. Isn't this different? | |
| Sep 11, 2020 at 16:15 | comment | added | Kashmiri | I really felt it's an average book. I wish I had time and money for blundell or Schroeder | |
| Sep 11, 2020 at 13:04 | comment | added | user400188 | @YasirSadiq That is where I got the majority of the proof from. I added only a few extra steps, it is a great textbook. | |
| Sep 11, 2020 at 12:52 | comment | added | Kashmiri | a similar proof can be found in the appendix of' Thermal physics by garg, bansal and ghosh'. | |
| Jan 3, 2019 at 3:51 | history | edited | user400188 | CC BY-SA 4.0 |
verified that two integrals I claimed equivalent actually are
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| Dec 21, 2018 at 2:55 | vote | accept | user400188 | ||
| Dec 21, 2018 at 2:53 | comment | added | user400188 | The fact that other directions of velocity, contribute so little to the final result, is actually quite interesting. I think it deserves a spot on the page for this reason. | |
| Dec 21, 2018 at 2:53 | comment | added | user400188 | @Thorondor It is a perfectly valid derivation, under the assumption that all velocities are perpendicular. Just provide an explanation at the start, that it only holds in this case. | |
| Dec 20, 2018 at 7:57 | comment | added | Thorondor | Thanks for taking the time to write this up! I believe this answer is correct. Should I delete mine? As you've shown, my answer was wrong, and I don't want to mislead future readers. | |
| Dec 19, 2018 at 9:13 | history | edited | user400188 | CC BY-SA 4.0 |
grammar error
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| Dec 19, 2018 at 9:03 | history | edited | user400188 | CC BY-SA 4.0 |
added explanation as to why it differs from another answer
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| Dec 19, 2018 at 8:54 | history | answered | user400188 | CC BY-SA 4.0 |