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Decibels and intensity

  1. Nov 18, 2008 #1
    1. The problem statement, all variables and given/known data
    if two firecrackers produce a sound level of 95 dB when fired simultaneously at a certain place, what will the sound level be if only one is exploded?

    2. Relevant equations

    dB=10 LOG I + 120

    3. The attempt at a solution
    would I use 2I instead of I making an equation like 95 = 10 log 2I + 120 and then solve for one I?
    Or set up the usual equation and then once I solve for I just divide it in half?
    Also, I know that when intensity doubles, it goes up by 3 decibels, so do I just assume that two firecrackers is double the intensity of 1 and just subtract 3 decibels from the original 95?
  2. jcsd
  3. Nov 19, 2008 #2


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    That's right.
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