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Homework Help: Traveling Sinusoidal Waves

  1. Nov 29, 2008 #1
    1. The problem statement, all variables and given/known data
    Two traveling sinusoidal waves are described by the wave functions
    y1 = (5.00m) sin[pie(4.00x - 1 200t)]
    y2 = (5.00m) sin[pie(4.00x - 1 200t -0.250y)]
    where x, y1, and y2 are in meters and t is in seconds.
    (a) What s the amplitude of the resultant wave?
    (b) What is the frequency of the resultant wave?

    2. Relevant equations
    y = (2Acos Phi/2) sin(kx- wt + Phi/2)

    3. The attempt at a solution
    The two waves are out of phase by 0.250
    therefore A = (2A cos Phi/2)
    I get the Amplitude to be 9.99 or 10m
    from 2 (5.00m) .25/2
    Do I need to do more for this? I know the answer but can't get there
  2. jcsd
  3. Nov 30, 2008 #2


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    Staff Emeritus
    Science Advisor
    Homework Helper

    Is it "-0.250y" or just "-0.250" for the phase in y2?

    It should be slightly lower. Was your calculator in radians mode when you calculated cos(0.25)?

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