A sound source emits 20.0 W of acoustical power spread equally in all directions. The threshold of hearing is 1.0 × 10^-12 W/m². What is the sound intensity level 30.0 m from the source? A) 92.5 dB B) 81.5 dB C) 1.77 × 10^-3dB D) 1.77 × 10^-3W E) -27.5 dB

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Quizplus · Accepted Answer

The sound intensity level (in dB) is calculated using the formula: $ L = 10 \log_{10} \left( \frac{I}{I_0} \right) $, where $ I $ is the intensity and $ I_0 $ is the threshold of hearing. First, find the intensity $ I $ at 30 m using $ I = \frac{P}{4\pi r^2} $, where $ P = 20.0 $ W and $ r = 30.0 $ m. Then, calculate $ L $.

A Sound Source Emits 20