The sound intensity is 0.0080 W/m2 at a distance of 10 m from an isotropic (same intensity in all directions) point source of sound.
(a) What is the power of the source?
(b) What is the sound intensity 5.0 m from the source?
(c) What is the sound level 10 m from the source? The threshold of human hearing
is I0 = 1.0 × 10 -12 W/m2 .