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Homework Help: Wave moving question diagram

  1. Oct 9, 2012 #1
    1. The problem statement, all variables and given/known data
    http://i1269.photobucket.com/albums/jj597/bubakazouba/114d22d10848ac93ac2fcea482ffe527_zpsedb41f24.jpg [Broken]
    the other line is a drawing of me trying to trace the wave(but of course its wrong,Im sry try to ignore it)
    the answer is A
    2. Relevant equations
    My teacher told me that when we get a question like this to determine the point that I want to track its path and look at its left to see whether the point on its left is higher or lower than it
    if it is lower then it will go downwards and vice versa.

    3. The attempt at a solution
    I tried that but it gets Q wrong, Q should get downward, why is it stationary?
    which leads to the other question how can any point on the wave remain stationary after a time.
    Last edited by a moderator: May 6, 2017
  2. jcsd
  3. Oct 9, 2012 #2


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    Homework Helper

    hi bubakazouba! :smile:

    each point can only move up or down (or be stationary)

    to find which, look at where it was a moment ago, and where it will be in a moment's time

    both times, Q is lower than it is now :wink:
  4. Oct 10, 2012 #3
    sorry i don't get it,
    there are two instants {a moment ago, in a moment's time}
    you said
    "both times Q is lower than it is now", Q now is lower than Q now?
    Last edited: Oct 10, 2012
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