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!

Relation between phase velocity and group velocity

  1. Oct 9, 2012 #1
    I know the physical meaning of phase as well as the group velocity.

    I want to know the mathematical relationship between the phase velocity and group velocity.

    Thanks a lot.
  2. jcsd
  3. Oct 9, 2012 #2
    If you know the definitions, you can easily find a relationship.
  4. Oct 9, 2012 #3
    It looks as if the group velocity is the derivative of phase velocity but I don't think I am correct.

    What's the exact relationship?

    Thanks a lot.
  5. Oct 9, 2012 #4
    The group velocity can be related to the derivative of phase velocity (in respect to k or λ
    ). It is not just equal to the derivative, it won't even make sens dimensionally. What relationship did you find?
  6. Oct 9, 2012 #5
    Could not find anything.
  7. Oct 9, 2012 #6


    User Avatar
    Gold Member

  8. Oct 9, 2012 #7
    I did not mean to look it up but to find it by direct calculation.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook