A very loud train whistle has an acoustic power output of 80 W.If the sound energy spreads out spherically,what is the intensity level in dB at a distance of 100 meters from the train? (I₀ = 10−¹² W/m²) A) 78.3 dB B) 88.0 dB C) 92.8 dB D) 95.0 dB

Question

Quizplus · Accepted Answer

First, we need to calculate the sound intensity at a distance of 100 meters:
I = P/4πr² = 80/(4π(100)²) = 2.54 x 10^-6 W/m²

Next, we can find the sound intensity level in dB using the formula:
IL = 10 log(I/I0) where I0 = 10^-12 W/m² (reference intensity)

IL = 10 log (2.54 x 10^-6/10^-12) = 88.0 dB

Therefore, the answer is B, 88.0 dB.

A Very Loud Train Whistle Has an Acoustic Power Output