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Homework Help: Ξ cm = 4.9 sin (1.06 x - 0.77 t) - Determine Travelling Speed of Wave

  1. Jan 17, 2010 #1
    1. The problem statement, all variables and given/known data

    The equation of a wave along the x-axis is given as: ξ cm = 4.9 sin (1.06 x - 0.77 t)
    in which ξ is the displacement. Units on the right hand side are 1/cm for К and 1/s for ω.
    Determine the the traveling speed of the wave.
    Express the result in the unit m/s and to three significant figures. If you must use scientific notation, please enter as follows: e.g. 0.000123 = 1.23E-4. Only answer in numerical values, no units. For negative numbers, leave no space between the negative sign and the number: e.g. right: -1.00, wrong: - 1.00.

    2. Relevant equations

    I would think V= w/k

    3. The attempt at a solution

    V = 0.77/1.06
    = 0.726

    This is the wrong answer
  2. jcsd
  3. Jan 17, 2010 #2


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    lambda = 2*pi/1.06
    frequency f = 2*pi/077
    v = f*lambda.
    Try this one.
  4. Jan 18, 2010 #3
    v = 48.3

    It says it is wrong. Are the units m/s?
  5. Jan 18, 2010 #4


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    Your initial method is correct. Try writing in the units to see what units your answer is in and then convert it if necessary.
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