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Homework Help: Reflected wave equation

  1. May 28, 2006 #1
    Consider a progressive wave represented by the equation,
    y = A[sin(wt – kx)]
    If it is reflected from a wall, what will probably be the equation of the reflected wave?
    I think it is y = A1[sin(wt + kx)]
    Is it right? Should a negative sign be given to the expression? Will there be a phase change of pi assuming the wall to be rigid boundary?
    Last edited: May 28, 2006
  2. jcsd
  3. May 28, 2006 #2
    There will be a phase change of [itex]\pi[/itex] if the wall is of a denser medium than the incident medium. Since the wall is rigid, this is correct. [itex]A_{1}[/itex] is determined from considerations of boundary conditions. That will tell you whether there should be a minus sign or not. You don't have to "give" it a negative sign.
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