Question

The diagram shows waves of sound travelling through the air. By which factor is the sound intensity decreased at 3 meters?

Answer 1

its a on edge just finished my exam

heres the diagram

Answer 2

The diagram is missing; however, we know that the intensity of a sound wave is inversely proportional to the square of the distance from the source:

`I(r)= (1)/(r^2)`
where I is the intensity and r is the distance from the source.

We can assume for instance that the initial distance from the source is r=1 m, so that we put

`I= (1)/(r^2)= (1)/((1)^2)=1`
The intensity at r=3 m will be

`I= (1)/(r^2)= (1)/((3)^2)= (1)/(9)`
Therefore, the sound intensity has decreased by a factor
`1/9`.