Since waves transfer energy from one point to another, one can define the power of a wave as the rate at which the wave transports energy. The intensity of a wave, in contrast, is the power relative to a certain surface. Consider a wave traveling across a surface perpendicular to the direction of propagation. The intensity I of the wave is defined as the ratio of the power P of the wave to the area A of that surface: I$=$PA $.$ Note that the surface may be real $($physical$,$ like an eardrum or a windowpane$)$ or mathematical. Quite frequently, we will be interested in the intensity produced by a relatively small source at a relatively large distance. If the source emits waves uniformly in all possible directions $($produces spherical waves$),$ the formula given here makes it possible to find the intensity at a distance r from the source: I$=$P$4$r$2.$ Note that, in all parts of this problem, assume that the source generates spherical waves, so that this intensity formula is applicable. Intensity is measured in watts per square meter $($W$/$m$2).$ All the information presented here is pertinent to any kind of wave. In this problem, we will be focusing on sound waves. A popular car stereo has four speakers, each rated at $60$ W $.$ In answering the following questions, assume that the speakers produce sound at their maximum power.Find the intensity I of the sound waves produced by one $60-$ W speaker at a distance of $1\mathrm{.}0$ m $.$ Find the intensity I of the sound waves produced by one $60-$ W speaker at a distance of $1\mathrm{.}5$ m $.$Find the intensity I of the sound waves produced by four $60-$ W speakers as heard by the driver. Assume that the driver is located $1\mathrm{.}0$ m from each of the two front speakers and $1\mathrm{.}5$ m from each of the two rear speakers.The threshold of hearing is defined as the minimum discernible intensity of the sound. It is approximately $1012$W$/$m$2.$ Find the distance d from the car at which the sound from the stereo can still be discerned. Assume that the windows are rolled down and that each speaker actually produces $0\mathrm{.}06$ W of sound, as suggested in the last follow$-$up comment