Why is the most probable energy different from the speed?

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The discussion centers on the distinction between the most probable energy and the most probable speed in the context of the Maxwell-Boltzmann distribution. It is noted that the most probable energy level does not equal the most probable speed squared multiplied by half the mass, leading to confusion about the physical interpretation of this difference. Participants explore the idea that energy levels may encompass a range of speeds, suggesting that an infinitesimal change in energy could cover a broader range of speed values than a similar change in speed. The mathematical relationships governing these distributions are emphasized, highlighting that averages and most probable values are not the same. Overall, the conversation seeks to clarify the physical implications of these statistical mechanics concepts.
  • #31
The complete solution is in #13. I still don't know, what else you need.
 
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  • #32
vanhees71 said:
The complete solution is in #13. I still don't know, what else you need.

Never mind, I figured it out, thanks. My calcuations in post #30 are wrong, I didn't pay attention when doing them. I was overlooking the fact that the relation between ##dE## and ##dv## is a function of ##v## while the probability itself is also a function of ##v##. If the relation between ##dE## and ##dv## were a constant, then then ##E_{max}## would correspond to ##v_{max}## .

Is there actually a mathematical way to explain why the maximum probability density in terms of energy ##E_{max}## is exactly half the energy that corresponds to ##v_{max}##?
 
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  • #33
JohnnyGui said:
I figured it out, thanks.

It doesn't look like it, since you come right back with the same question:

JohnnyGui said:
Is there a mathematical way to explain why the maximum probability density in terms of energy ##E_{max}## is exactly half the energy that corresponds to ##v_{max}##?

The math has already been discussed quite sufficiently in this thread. I think the discussion has run its course.

Thread closed.
 
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