Question

A woman stands a distance d from a loud motor that emits sound uniformly in all directions. The sound intensity at her position is an uncomfortable 2.9×10-3 W/m2. At a distance 1.5 times as far from the motor, what are (a) the sound intensity and (b) the sound intensity level relative to the threshold of hearing?

Answer 1

SOLUTION:

PART A:

We know that, Intensity of the sound is given by:

P - Power of sound.

r - distance from the sound source.

Therefore, Sound intensity is given by:

We have,

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PART B:

We have:

Intensity of sound,

Threshold intensity,

Therefore, Sound level is given by: