A microphone in the ocean is sensitive to sounds emitted by porpoises. To produce a usable signal, sound waves striking the microphone must have an intensity of 10.7 dB. If porpoises emit sound waves with a power of 0.0491 W, how far can a porpoise be from the microphone and still be heard? Disregard absorption of sound waves by the water.
Required intensity of sound (I) = 10.7 dB
<br>Available power = 0.0491W
<br>Let us say that the purpoise is at a distance 'x' such that it emits sound which produces the required ...