Question

6-1 Two speakers emit sound waves with frequency 4.27 kHz s pts by the same oscillator so that they are in phase with each other. I place the They are driven speakers side-by-side, and I stand across the room from them. If someone moves one of the speakers towards me, I hear the total intensity drop and then rise again. How far had they moved the speaker at the point whereI heard a minimum intensity due to destructive interference of the sound waves from the two speakers? The speed of sound is 343 m/s. cm (t 0.02 cm)

Answer 1

Given that

Frequency (f)=4.27 kHz

speed of sound (v)=343 m/s

The distance moved the speaker to the point where I heard a maximum intensity due to destructive interference of the sound waves from the two speakers is half wavelength

so,

lamda = v/f

=(343 m/s)/4270 Hz

=0.08032 m

then,

half wavelength=(0.08032 m)/2

=0.04016 m

or

=4.02 cm

     =4.0 cm

so moving a speaker 4.0 cm distance to heard minimum intensity.