Two in-phase loudspeakers are placed along a wall and are separated by a distance of 4.00 m.They emit sound with a frequency of 514 Hz.A person is standing away from the wall,in front of one of the loudspeakers.What is the closest distance from the wall the person can stand and hear destructive interference? The speed of sound in air is 343 m/s.
A)0.34 m
B)0.37 m
C)0.73 m
D)1.2 m
E)1.6 m

Question

Quizplus · Accepted Answer

Destructive interference occurs when the path difference is an odd multiple of half-wavelengths. The wavelength is calculated as speed/frequency = 343/514 ≈ 0.667 m. The path difference for the first instance of destructive interference is λ/2 = 0.667/2 ≈ 0.334 m, which corresponds to choice A.

Two In-Phase Loudspeakers Are Placed Along a Wall and Are