At point A, 3.0 m from a small source of sound that is emitting uniformly in all directions, the sound intensity level is 53 dB. (a) What is the intensity of the sound at A? (b) How far from the source must you go so that the intensity is one-fourth of what it was at A? (c) How far must you go so that the sound intensity level is one-fourth of what it was at A? (d) Does intensity obey the inverse-square law? What about sound intensity level?

A sound wave travels through air at 20 °C. The decibel level at a distance of 19.4 m from the source is measured to be 85.2 dB. What is the dB level at a position that is 7.17 m closer? Assume the density of air is 1.20 kg/m3 and that the source produces spherical wave fronts.

A trumpet creates a sound intensity level of 9.30  101 dB at a distance of 1.00 m. (a) What is the sound intensity of a trumpet at this distance? W/m2(b) What is the sound intensity of five trumpets at this distance? W/m2(c) Find the sound intensity of five trumpets at the location of the first row of an audience, 7.00 m away, assuming, for simplicity, the sound energy propagates uniformly in all directions. W/m2(d) Calculate the decibel level of the five trumpets in the first row. dB(e) If the trumpets are being played in an outdoor auditorium, how far away, in theory, can their combined sound be heard? m(f) In practice such a sound could not be heard once the listener was 2-3 km away. Why can't the sound be heard at the distance found in part (e)? Hint: In a very quiet room the ambient sound intensity level is about 30 dB

A very noisy chain saw operated by a tree surgeon emits a total acoustic power of 34.0 W uniformly in all directions. (A) At what distance from the source is the sound level equal to 110 dB? Express your answer in meters. (B) At what distance from the source is the sound level equal to 58 dB? Express your answer in kilometers.