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. D) Inconsistencies in the music play resulting in spotty sound wave production.

Answer 1

Option (a) is correct.

Change in volume during the band concert might have been caused by the constructive and destructive interference of sound waves.

Interference is the process of redistribution of energy when two or more waves superimpose on each other.When two sound waves which are in phase superimpose on each other, constructive interference takes place. During constructive interference , the amplitude of resulting waves increases.Thus the loudness of sound increases.

When two sound waves which are out of phase superimpose on each other, destructive interference takes place. During destructive interference , the amplitude of resulting waves decreases.Thus the loudness of sound decreases.

Answer 2

Its A) Constructive and destructive interference of sound waves.