Answer:
Intensity
Explanation:
The intensity of a sound wave is equal to the ratio between to the power emitted by the source divided by the area of the spherical surface through which the wave propagates:
[tex]I=\frac{P}{4\pi r^2}[/tex]
where
P is the power
[tex]4\pi r^2[/tex] is the area of the spherical surface
r is the distance from the source
As we see from the formula, the intensity is inversely proportional to the square of the distance from the source:
[tex]I\propto \frac{1}{r^2}[/tex]
so, intensity is the correct answer.
