Sound Intensity and Human threshold for hearing

  1. Is it possible to have a negative sound intensity level?
    A sound that is below the threshold of human hearing has......

    (A) a negative intensity level (in dB).
    (B) a negative intensity (in W/m^2 ).
    (C) an intensity level of zero.
    (D)an intensity level less than 1 dB , but greater than 0.

    I think I know the answer but I don't want to guess wrong and lose points.



    Does it have to do with anything like I/Io or I=power/area ??


    I think the answers is A or B..but I don't see the difference in between dB and W/m^2 i thought they are the same thing.
     
  2. jcsd
  3. I think you're confusing yourself. Look at the units in answers A and B and ask yourself how each could physically be negative.
     
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