Question

The loudness, L , of a sound (measured in decibels, dB) is inversely proportional to the square of the distance, d , from the source of the sound.

A person 14 feet from a jetski, it is 75 decibels loud.

How loud is the jetski when the person is 45 feet away?

Answer 1

Answer

7.2593 decibels

Explanation

L ∝ 1/d² Inserting the constant of variation,

L = k/d²

k = Ld²

  = 75 × 14²

  = 14,700

When d = 45 feet;

L = 14,700/45²

  = 14,700/2,025

 = 7.2593 decibels