Two In-Phase Loudspeakers Are Placed 6

Multiple Choice

Two in-phase loudspeakers are placed 6.00 m apart along one wall of a room. They emit sound with a frequency of 512Hz. Starting at the location of one of the loudspeakers, a microphone is moved in a direction perpendicular to the wall until constructive interference is detected for the first time. How far is the microphone from the wall at that point? The speed of sound in air is 330 m/s.

A) 0.141 m
B) 0.664 m
C) 0.203 m
D) 0.138 m
E) 0.282 m