The sound intensity level of a rock band 1400 m away at the

The sound intensity level of a rock band 140.0 m away at the back of a stadium is 100 dB. How much sound energy per second does the rock band generate?

Solution

solution

intensity level = 100 dB = 1 X 10^-2 W / m²

sound intensity = sound power / (4 pi R²)

sound power = 1 X 10^-2 X 4 X 3.14 X (140)²

   = 2461.76 W

so, sound energy per second = sound power = 2461.76 W = 2461.76 J/sec