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Homework Help: Find an FM Radio station's wavelength, frequency given

  1. Sep 22, 2007 #1
    [SOLVED] Find an FM Radio station's wavelength, frequency given

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

    An FM radio station broadcasts at a frequency of 101.3 MHz. What is the wavelength?

    2. Relevant equations

    Vsound = 343m/s @ 20 deg C
    λ = v/f

    3. The attempt at a solution

    I used the formula λ = v/f and got something similar to 3.38 * 10 ^ -6 meters...kinda small, and the MHz/Hz difference doesnt matter since that is a decimal place thing, which doesn't change the value...anyways..the computer says the answer is 2.96 ....anybody know why?

    so i moved on to the next subproblem:

    What is the frequency of a sound source that produces the same wavelength in 20 deg C air?

    The answer is 116 Hz , which makes sense once you use 2.96 and Vsound = 343 and manipulate the formula. And since the question asks about 20 deg C, I then thought that perhaps the first question was refering to 0 deg C, but still I didnt get 2.96, so it is still incorrect... what am I doing wrong?

    Last edited: Sep 22, 2007
  2. jcsd
  3. Sep 22, 2007 #2


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    Staff Emeritus
    Science Advisor
    Gold Member

    A radio station broadcasts radio waves which are EM waves not sound waves. Thus v for the radio station will be the speed of light.
  4. Sep 22, 2007 #3

    ......................oh lol

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