Two stereo speakers mounted 4.52 m apart on a wall emit identical sound waves. You are standing at the opposite wall of the room at a point directly between the two speakers. You walk 2.11 m parallel to the wall, to a location where you first notice that the sound intensity is essentially zero. If the wall along which you are walking is $10.7 \mathrm {~m}$ from the wall with the speakers, what is the wavelength of the sound waves? The walls are cushioned to absorb sound reflections.

Question

Quizplus · Accepted Answer

The path difference between the sound waves from the two speakers at the point of zero intensity is half a wavelength, which is the condition for destructive interference. Using the geometry of the situation and the Pythagorean theorem, the wavelength can be calculated to be approximately 1.71 m.

Two Stereo Speakers Mounted 4 10.7 m10.7 \mathrm {~m}10.7 m From the Wall with the Speakers, What Is the Wavelength

Two Stereo Speakers Mounted 4 $10.7 \mathrm {~m}$ From the Wall with the Speakers, What Is the Wavelength