Talk:Thermal velocity

Error bars and confidence limits for speed[edit]

With a formula like

v_{\mathrm {th} }={\sqrt {\frac {3k_{B}T}{m}}}

for the root-mean-square velocity in three dimensions, what are the confidence limits and/or error bars? For example, for what speed range $(v_{l},v_{h})$ is it the case that there is a 2.5% chance that a given molecule's speed will be below $v_{l}$ and there is a 2.5% chance that a given molecule's speed will be above $v_{h}$ ? — Preceding unsigned comment added by 104.129.194.134 (talk) 13:58, 17 August 2018 (UTC)[reply]

Air molecules should be close enough to a Boltzmann distribution. There is the complication of 1D vs. 3D, but other than that. The numbers given are the average in one of six different ways. With a large number of molecules, the average itself will have a very small error bar. Otherwise, the actual distribution itself is described in Maxwell–Boltzmann distribution. Gah4 (talk) 23:05, 5 January 2021 (UTC)[reply]

which?[edit]

The article gives six different ways to figure the thermal velocity, and then a table. It doesn't indicate which of the six is used in the table. Gah4 (talk) 23:06, 5 January 2021 (UTC)[reply]

Make clear that thermal velocity does not lead to macroscopic motion[edit]

I think it should be made clear that thermal velocity does not lead to macroscopic motion, as one could expect when seeing non-zero velocities due to temperature. Instead, the velocities are in random directions and cancel out on average. This is already alluded to by mentioning the difference between speed and velocity and could be explained there (by someone who can formulate it more rigorously than me). — Preceding unsigned comment added by 141.24.136.178 (talk) 09:05, 14 October 2021 (UTC)[reply]

Width of the peak?[edit]

What is meant by "width of the peak in the Maxwell–Boltzmann particle velocity distribution"? Width at what height? 90% of the peak height? Something else? Or does it just mean to convey that the peak shape is qualitatively getting broader/flatter with higher temperatures? 145.40.208.28 (talk) 22:51, 16 October 2023 (UTC)[reply]