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Homework Help: Mechanical Waves, The Doppler Effect

  1. Jan 18, 2009 #1
    1. The problem statement, all variables and given/known data

    At the Winter Olympics, an athlete rides her luge down the track while a bell just above the wall of the chute rings continuously. When her sled passes the bell, she hears the frequency of the bell fall by the musical interval called a minor third. That is, the frequency she hears drops to five sixths of its original value.

    a) Find the speed of sound in the air at the ambient temperature -15 degrees Celsius

    b) Find the speed of the athlete.

    2. Relevant equations

    The Doppler Equation: f prime = f*(v+vo)/(v-vs)

    3. The attempt at a solution

    I got part a) using the following equation: 331+ (0.6)(-15.0)= 322 m/s

    For part b), I tried to use the Doppler equation, setting vs= 0 since the source of the sound is stationary. I plugged everything else in like this :

    x*(322+Vo)/(322-0)=5/6 x

    This way the x's would drop out, and I would have an answer of 53.7 m/s but this is incorrect. I don't know if I am close or if I am not even on the right track.
    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
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