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Homework Help: Electromagnetic Radiation-Really easy but I am stuck

  1. Dec 18, 2006 #1
    1. The problem statement, all variables and given/known data

    How many wavelengths of radiation emitted by a 60 Hz electrical transmission line would it take to span the North American continent (a distance approximation 5.0*10^3 km).

    f=60Hz
    d=5.0*0^3 km=5.0*10^6 m

    2. Relevant equations

    v=fλ
    Δd=vΔt

    3. The attempt at a solution

    Δt=d/v
    = 1.67*10^-2

    If speed is c then wavelength should equal c/f=3.0*10^8/60
    =5.0*10^6

    Which is absoloutely wrong since answer is 1.0.

    Please help me and thanks in advance.
     
  2. jcsd
  3. Dec 18, 2006 #2

    Doc Al

    User Avatar

    Staff: Mentor

    Not sure what you are calculating here.

    That's all you need. Hint: Units!

    Not as wrong as you think! :wink:
     
  4. Dec 18, 2006 #3
    Thank You very much!
     
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