At a distance of 2.00 m from a point source of sound,the intensity level is 80.0 dB.What will be the intensity level at a distance of 4.00 m from this source? The lowest detectable intensity is 1.0 × 10^-12 W/m². A)77.0 dB B)74.0 dB C)60.0 dB D)40.0 dB E)20.0 dB

Question

Quizplus · Accepted Answer

Using the inverse square law for sound intensity, we know that the intensity decreases with the square of the distance from the source. Therefore, if the distance is doubled, the intensity will decrease by a factor of 4.

So, at 4.00 m from the source, the intensity level will be:

IL = 80 dB - 20 dB (log(4.00 m / 2.00 m))
IL = 74.0 dB

Therefore, the answer is B.

At a Distance of 2