What is the intensity of sound waves produced by a trumpet at a distance of 1.6 m when the power output of the trumpet is 0.30 w?

The intensity of a wave is given by the ratio between the power  P of the source and the surface A over which it is calculated:


For the sound wave in this problem, the power is P=0.30 W. Since a sound wave propagates radially, the area that we should use is the surface of of a sphere with radius r=1.6 m:


Therefore, the intensity is

By dividing you can find the answer