A rock band give rise to an average sound level of `102 dB` at a distance of `20 m` from the center of the band . As an approximation , assume that the band radiates sound equally into a sphere. What is the sound power output of the band?

Explanation

`L = 10 log_(10) ((I)/(I_(o)))`
`:. 10^(2) = 10 log ((I)/(10^(-12)))`
Solving we get, `I = 1.59 xx10^(-2) W//m^(2)`
`I = (P)/(4 pi r^(2)`
`:. P = (I) (4 pi r^(2))`
`= (1.59 xx10 ^(-2)) (4 pi) (20)^(2)`
`= 80 W`