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Out of phase waves

  1. Jan 14, 2017 #1
    1.JPG


    2. Relevant equation

    3. The attempt at a solution

    I can see straight away that the waves are 90 degrees out of phase so pie/2.

    But how is X ahead of Y? It looks like Y is ahead of X by pie/2.
     
  2. jcsd
  3. Jan 14, 2017 #2

    berkeman

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    Staff: Mentor

    The horizontal axis is time, so X is oscillating up before Y is oscillating up. Look at the origin -- X is full size, and Y is just starting to move positive from zero... The key is to look at where the two waveforms are at the same time (say t=0) and ask yourself which one is "leading" the other. Makes sense?
     
  4. Jan 14, 2017 #3

    haruspex

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    Another way to look at it..
    "Ahead" means earlier in time. Earlier in the graph is to the left. The X curve is left of the Y curve by one quarter period.
     
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