The low-frequency speaker of a stereo set has a surface area of 0.07 m2 and produces 1.63 W of acoustical power. What is the intensity at the speaker (in W/m2)?

I = 81.5 W/m^2

Explanation:

In order to calculate the intensity of the sound at the speaker, you use the following formula:

         (1)

P: power of the speaker's sound = 1.63W

A: surface area of the stereo set = 0.07m^2

You assume that the intensity of the sound at the speaker depends only of the surface area of the stereo set. Furthermore, you consider that the wave front of the sound is approximately plane.

You replace the values of the parameters in the equation (1):

The intensity of the speaker's sound at the speaker is 81.5 W/m^2