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!

Find dispersion relation using periodicity

  1. Oct 11, 2009 #1
    Ok so heres another problem that i just completely dont understand at all. Thanks for your help.

    A linear chain consists of 2N equally spaced identical particles with mass m and speration a, coupled by springs with alternating constands k1 and k2. Use the periodicity of the system to find the dispersion relation and sketch the resulting function ω (q). Hint: Assume

    η2j = [tex]\alpha[/tex]e^i[2jaq-ωt] , η2j+1 = βe^i[(2j+1)aq - ωt]
     
  2. jcsd
  3. Oct 12, 2009 #2

    gabbagabbahey

    User Avatar
    Homework Helper
    Gold Member

    What do η2j and η2j+1 represent? What does 'q' represent?
     
  4. Oct 12, 2009 #3
    I dont know. This is what the professor assigned.
     
  5. Oct 12, 2009 #4

    gabbagabbahey

    User Avatar
    Homework Helper
    Gold Member

    Ask your professor then.

    How on Earth do you expect to show that η2j =[itex]\alpha[/itex] e^i[2jaq-ωt], if you have no idea what the variables η2j and 'q' represent?!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Find dispersion relation using periodicity
  1. Dispersion relations (Replies: 15)

Loading...