Calculating Distance for 140dB Loud Rock Concert Power Output of 93W

[Mike77]

A point source emits sound waves with a power output of 93 W. At what distance will the decibel reading be 140 dB, which is noise level of a loud indoor rock concert?
Answer in units of meters.

For this one I tried using the equation:

I = P/4(Pi) r^2

I'm not a physics major and have not done anything physics related since high school so any help would be appreciated.

Thanks

 

[Mike77]

I = intensity
P = Power
r = distance

 

[ehild]

The human ear senses the intensity of sound on a logarithmic scale. The loudness or sound level in decibels is defined with respect to the minimum intensity detectable by the human ear,

I₀=10^-12 W/m².

L=10*log(I/I₀).


ehild