Question

Mr. and Mrs. Tew attended this summer band concert to hear their son play his violin. They sat in the back row. They noticed that during the concert, the music seemed to changed in volume; sometimes it was very loud and other times they could barely hear it. They finally got up and moved to the fourth row, directly in front of the band. The problem seemed to lessen. What might have caused this change in volume during the band concert? A) Constructive and destructive interference of sound waves. B) Sound waves reflecting off of the ceiling, walls, and other hard surfaces. C) Sound waves being absorbed by the walls and curtains in the concert hall. Eliminate D) Inconsistencies in the music play resulting in spotty sound wave production.

Answer 1

A)Constructive and destructive interference of sound waves.

Answer 2

Option (a) is correct.

The loudness of sound increased or decreased because of the constructive or destructive interference. interference is a process of redistribution of energy when a number of waves superimpose .

Constructive interference occurs when the waves are in phase . Because of the constructive interference,the amplitude of the resultant wave increases and thus the loudness increases.

Destructive interference occurs when the waves are out of phase . Because of the destructive interference,the amplitude of the resultant wave decreases and thus the loudness decreases.