Two speakers on a horizontal axis both emit 440 Hz sound waves. The two speakers are π radians out of phase. If there is to be a maximum constructive interference what is the minimum separation distance between the two speakers?

1 Answer
Mar 17, 2018

0.39 meters

Explanation:

Because the two speakers are off by π radians, they are off by half a cycle. To have maximum constructive interference, they must line up exactly, meaning one of them must be shifted over half a wavelength.

The equation v=λf represents the relationship between frequency and wavelength. The speed of sound in air is approximately 343 m/s, so we can plug that into the equation to solve for λ, the wavelength.

343=440λ
0.78=λ

Finally, we must divide the value of the wavelength by two because we want to shift them over half a cycle.

0.782=0.39 meters, which is your final answer.