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Homework Help: Measuring the doppler-effect

  1. Mar 1, 2012 #1
    1. The problem statement, all variables and given/known data


    I did an experiment a couple of weeks ago to measure the doppler-effect. I have used a pendulum with a microphone attached to it. At one end i put a speaker wich produces a sound with f =440 hz. T of the pendulum = 1,86 s. Vmax = 1,69 m/s. But if i try to measure T in my diagram it doesnt come near the solution i get with the doppler-equations.

    I have done this in my diagram:

    1800 - 1100 = 700 ms

    7T = 700 ms => T = 100 ms = 0,1 s

    I get f ≈ 10 hz (see doppler-effect2)

    2. Relevant equations

    I used fw=fb(1 + (vw/v)) and fw=fb(1-(vw/v)) and i got fw = 442 hz when the microphone is moving towards the speaker and fw = 437 hz when it moves away from it.

    3. The attempt at a solution

    I have tried to change the time-axes with a other timescale. But i dont think that's the solution. I know v is not constant. I don't see a way to link my experiment with the theory.

    I hope someone can help me with this.

    Attached Files:

  2. jcsd
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