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FWHM of velocity distribution

  1. Jul 20, 2014 #1
    Hi

    FWHM on a velocity distribution provides me with a specific velocity. What does FWHM say about the velocity distribution, I mean, does FWHM give me the most probable velocity of the distribution or something like that?

    Thanks
     
  2. jcsd
  3. Jul 20, 2014 #2

    Simon Bridge

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  4. Jul 20, 2014 #3

    Vanadium 50

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    No, that's the mode. It might or might not be anywhere near the mean.
     
  5. Jul 20, 2014 #4

    Simon Bridge

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    Depends on the distribution aye - I'm used to FWHM being used for pretty symmetrical distributions though.
     
  6. Jul 20, 2014 #5

    Vanadium 50

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    Consider the Maxwell-Boltzman distribution - surely a common (if not the most common) velocity distribution. It's not all that symmetrical - there's a long tail to the right, and thus the average and most probable velocities differ by a factor of 2/sqrt(pi).
     
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