Question

A source emits sound uniformly in all directions. There are no reflections of the sound. At a distance of 12 m from the source, the intensity of the sound is 3.5 × 10-3 W/m2. What is the total sound power P emitted by the source?

Answer 1

1.58 W

Step-by-step explanation:

Since the sound spreads uniformly in all directions, it must be in a form of a circle with radius of 12 m. So the area of the circle is

`A = \pi r^2 = \pi 12^2 = 452.389 m^2`

From the intensity of the sound we can calculate the power at 12 m

`P = AI = 452.389 * 3.5*10^(-3) = 1.58 W`