The decibel level, D, of sound is given by the equation

where I is the intensity of the sound and I₀ = 10^-12 watt per square meter.

(a) If the shout of a single person measures 80 decibels, how loud will the sound be if two people shout at the same time? That is, how loud would the sound be if the intensity doubled?

(b) The pain threshold for sound is 125 decibels. If the Athens Olympic Stadium 2004 (Olympiako Stadio Athinas €˜Spyros Louis€™) can seat 74,400 people, how many people in the crowd need to shout at the same time for the resulting sound level to meet or exceed the pain threshold? (Ignore any possible sound dampening.)

Transcribed Image Text:

D = 10 log|