Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

How do you work out the phase difference between 2 waves?

  1. Jan 4, 2010 #1
    The title is all i want to know really.

    Any help much appreciated

    Also, what is a superposition pattern?
  2. jcsd
  3. Jan 4, 2010 #2


    User Avatar
    Gold Member

    I guess it really depends on what you are able to measure.
    But basically, if you have two waves of the same frequency, let's say one is sin(t) and one gets shifted over (think of it visually) then this shift can be represented by an additional term like so sin(t+θ).
    So, θ is the "phase shift" you are looking for (in radians).
    But like I said, the way this is done depends (at least I think it does) on the situation, because I can think of two different ways to do it. One would use the time (or whatever the independent variable is) difference between the two waves. The other method would use a ratio of the displacements at a certain point. Just draw the two waves and see if you can figure out how to find θ geometrically from what you know.

    A superposition is like adding the two waves. For example, using the above wave and it's shifted wave the function for the superposition between the two would be:
    superposition = sin(t) + sin(t+θ)
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook