Interference with two speakers

[gills]

Homework Statement

Two loudspeakers, A and B, are driven by the same amplifier and emit sinusoidal waves in phase. The frequency of the waves emitted by each speaker is 172 Hz. You are 8.00m from speaker A. Take the speed of sound in air to be 344m/s .

What is the closest you can be to speaker B and be at a point of destructive interference?
Express your answer in meters


I really don't have a clue on how to solve this problem.

 

[gills]

destructive interference occurs at half wavelengths. Therefore with the quantities given, solve for wavelength which = 2m. Therefore the closest you can be to speaker B is 1 m and possibly experience destructive.

What a joke.

 

[Dick]

Uh, good job! It was actually a pretty good question. You nailed it.