1. Not finding help here? Sign up for a free 30min 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!

Question about origin of wave number K in wave equations

  1. Apr 28, 2013 #1
    1. The problem statement, all variables and given/known data

    Hey All,

    I'm hoping that you might be able to help me understand where the wave number "k" referred to in equations 6.62a and b below comes from. It makes sense to me that IF k=(2mE/hbar2) normally, that 6.62b would have E-V instead of E. That this change is made makes me think that it must have something to do with the kinetic energy, as I am assuming that E-V signifies kinetic energy, but I just don't know how to get any value of K to start with or how to derive either of the values shown above. I would really like to know exactly what K means/represents and how to derive its value for myself

    Any help would be appreciated.


    Screen_Shot_2013_04_28_at_7_34_37_PM.png
     
  2. jcsd
  3. Apr 28, 2013 #2
    I actually may have just asked a very dumb question.

    I just realized that by the definition given in my book, I can at least come up with the values of k given, though I still don't really understand what they mean.

    I saw that:

    k=2π/lambda = p/hbar = (p^2/hbar^2)^.5 = (2mE)^.5 / hbar.

    If anyone could help me understand what this means, or what the PHYSICAL significance of this value (other than its being 1/m in units) is, I would be super grateful.
     
  4. Apr 29, 2013 #3
    It tells you the amount of waves that will fit in one meter. The inverse of the wavelength that is. Say it is 1/4 meter wavelength. Then we get 4 wavelengths per meter. The 2π changes it into a phase difference with units rad/m. So the wavelength increases in the region of the potential barrier. The particle becomes more wavelike or tenuous in nature. k is more correctly called the angular wave number of the wave.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Question about origin of wave number K in wave equations
  1. Question about waves (Replies: 3)

Loading...