Question

Two speakers emit sound waves with frequency 4.55 kHz. They are driven by the same oscillator so that they are in phase with each other. I place the 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 where I heard a minimum intensity due to destructive interference of the sound waves from the two speakers? The speed of sound is 343 m/s

Answer 1

d=3.76 cm

Step-by-step explanation:

Given that frequency ,f= 4.55 KHz

Speed of sound = 343 m/s

We know that for sound

C= f λ

Where C is the velocity of sound

f is the frequency

λ is the wavelength

So now by putting the values

C= f λ

343= 4550 λ

λ=7.53 cm

We know that for destructive phase the difference in phase is π so the difference in distance will be λ/2.

So distance ,d= λ/2.

d=7.53/2 cm

d=3.76 cm

So they will move at a distance of 3.76 cm to hear minimum intensity of sound.