Sound Intensity and Human threshold for hearing

[mssweeteypie]

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.

 

[TVP45]

I think you're confusing yourself. Look at the units in answers A and B and ask yourself how each could physically be negative.