1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Most Probable Speed - Atoms From An Oven

  1. Jan 20, 2013 #1
    Hi there,

    I'm looking to find the most probable speed of atoms ejected from an oven.

    Temp (T) is 900°C (so 1173.15K).

    The material is aluminium with molar mass 0.027kg mol-1

    I've got the formula vmp=√(2kT/m)

    I'm fine with everything above, but I'm not sure what value to use as the Boltzmann constant k.

    Can anyone please help me here? Do I have the right equation and what value for the constant should I use (sounds silly, but it changes depending upon units. I've tried a couple but get silly tiny speeds out. I think I should expect something in the region of a few hundred metres per second).

    Many thanks

    Bob
     
  2. jcsd
  3. Jan 20, 2013 #2

    AlephZero

    User Avatar
    Science Advisor
    Homework Helper

    In SI units:
    K = 1.38e-23 J/K
    m = mass of one molecule = 0.027/6.022e23 kg
    T = 1173 K

    ... which gives a velocity of "hundreds of m/s" as you expected.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Most Probable Speed - Atoms From An Oven
Loading...