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Homework Help: Sound frequency problem

  1. Nov 14, 2005 #1
    Hi, everyone I'm really baffled by this question here. So I was wondering if anyone could help me.
    Question:
    If two successive overtones of a vibrating string are 360 Hz and 400 Hz, what is the frequency of the fundamental?
     
  2. jcsd
  3. Nov 14, 2005 #2

    Astronuc

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    Well the overtones are an integer multiple of the fundamental frequency, f, and if they are successive, then one has nf and (n+1)f.

    What would the integers be for 360 Hz and 400 Hz?
     
  4. Nov 14, 2005 #3
    Yes thats the part that troubles me. I don't know how to find the integers.
     
  5. Nov 15, 2005 #4
    So can anybody plz help me?
     
  6. Nov 15, 2005 #5

    Astronuc

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    Try nf = 360 Hz, and (n+1)f = 400 Hz,

    which leads one to (n+1)f - nf = 400 - 360 Hz => f = 40 Hz.

    so 9f = 9 * 40 Hz = 360 Hz, and 10 * 40 Hz = 400 Hz.
     
  7. Nov 15, 2005 #6
    oh now i get it, thanks
     
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