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Homework Help: Speed of sound/light question

  1. Apr 25, 2006 #1
    A celebrity holds a press conference, which is televised live. A television viewer hears the sound picked up by a microphone directly in front of the celebrity. This viewer is seated 3.3 m from the television set. A reporter at the press conference is located 5.3 m from the microphone and hears the words directly at the very same instant that the television viewer hears them. Using a value of 343 m/s for the speed of sound, determine the maximum distance between the television viewer and the celebrity.

    I have derived the equations for each situation. I have t1= s1/v for the time for the sound to reach the tv viewer, t2=s2/v for the time for the sound to reach the reporter and t=s/c for the time it takes the EM wave to reach the tv set, but so far, I am not sure how to combine these equatios. I thought that t2 should equal t1 since it says the sounds hits them at the same instant, but this doesn't seem to work. Can anyone help me out with this one?
  2. jcsd
  3. Apr 26, 2006 #2


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    t1 + t = t2

  4. Apr 26, 2006 #3

    Andrew Mason

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    The difference in sound paths is two metres. How long does it take for the sound to travel 2 m.? What distance would an EM signal or light travel in that time?

  5. Apr 26, 2006 #4
    Thanks AM, that made it very easy.
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