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Homework Help: Transverse displacement, tricky MC

  1. Jun 15, 2008 #1
    1. The problem statement, all variables and given/known data

    The transverse displacement of a streched string from equilibrium as a function of time and position is given by:
    y=0.13cos(3x+27t). x and y are in m; t is in s.
    (Select T-True, F-False, G-Greater than, L-Less than, E-Equal to, If the first is T and the rest F, enter

    A) The speed of the wave is ..... 8 m/s
    B) The wavelength is ..... 1 m
    C) The wave moves in the positive x direction
    D) The period is ..... 0.1 s

    2. Relevant equations

    The only one i was able to solve for was D, using

    [tex]\omega[/tex] = [tex]\frac{2\pi}{T}[/tex]

    3. The attempt at a solution

    Solving for T: T= 2pi/27 gives T= 0.23 s. This designates D as G (greater than).
    I cant really figure out how we get the others from T... My main problem is Finding velocity. If i find velocity, i can find the rest. My secondary problem is finding out the direction of the wave.

    p.s. even my tutor couldn't get this one.
    Last edited: Jun 15, 2008
  2. jcsd
  3. Jun 15, 2008 #2

    Doc Al

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    Staff: Mentor

    Last edited by a moderator: Apr 23, 2017
  4. Jun 15, 2008 #3
    Got it worked out, thanks. My problem was not recognizing what k was in this situation (angular wave number).
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