Arock band playing an outdoor concert produces sound at 120 db 5.0 m away from their single working loudspeaker. ignore sound reflected from walls and other objects and consider sound originating directly from the speakers.

a. what is the sound intensity level 35 m from the speaker?
b. how far away from the speaker should you stand to ensure the intensity does not exceed 80 db?

Given that

β= 120 dB at 5 m

We know that sound intensity given as

I= 1 W/m²

Power producing by loud speaker

P = I  x 4πr²

P=314.15 W

a)

Let take intensity at 35 m is I'

r'=35 m

I'=P/4πr'²

I'=0.0204 W/m²

b)

Given that

β'= 80 dB

I'=10⁻⁴ W/m²

Let's take at distance r  intensity is 80 dB

P=314.15 W

P = I'  x 4πr'²

314.15 = 10⁻⁴  x  4πr'²

r'=500.11 m

well, you would divide 135 by 33 to get your answer. then that is how many seconds it would take. boardman should fly about 132 m or 4.090909090909091 seconds.

hi there!

out of the two, (b) precision would be more reasonable.   however, both a and b could be pretty reasonable.

-awesomerepublic   : )