Use the decibel scale to answer the question.
-How does the intensity of sound from a concert speaker at a distance of 20 meters compare to the intensity at a distance of 140 meters?
A)Factor of 7 weaker at 140 m.
B)Factor of 49 weaker at 140 m.
C)Factor of 196 weaker at 140 m.
D)Factor of 70 weaker at 140 m.

Question

Quizplus · Accepted Answer

The intensity of sound decreases with the square of the distance from the source, so if the distance increases by a factor of 7 (from 20 m to 140 m), the intensity decreases by a factor of 7^2, which is 49.

Use the Decibel Scale to Answer the Question