Two people are talking at a distance of 3.0 m from where you are and you measure the sound intensity as 1.1 × 10^-7 W/m². Another student is 4.0 m away from the talkers. What sound intensity does the other student measure? A) 6.2 × 10^-8 W/m² B) 1.5 × 10^-7 W/m² C) 8.3 × 10^-8 W/m² D) 7.8 × 10^-7 W/m² E) 2.5 × 10^-8 W/m²

Question

Quizplus · Accepted Answer

The intensity of sound decreases with the square of the distance from the source. So, the intensity at 4.0 m will be (3.0 m/4.0 m)^2 = 0.5625 times the intensity at 3.0 m. Therefore, the intensity at 4.0 m will be 1.1 × 10^-7 W/m^2 * 0.5625 = 6.2 × 10^-8 W/m^2.

Two People Are Talking at a Distance of 3