Small speakers A and B are driven in phase at 725 Hz by the same audio oscillator. Both speakers start out 4.50 m from the listener, but speaker A is slowly moved away (Fig. E16.34).

(a) At what distance d will the sound from the speakers first produce destructive interference at the listener€™s location?

(b) If A is moved even farther away than in part (a), at what distance d will the speakers next produce destructive interference at the listener€™s location?

(c) After A starts moving away from its original spot, at what distance d will the speakers first produce constructive interference at the listener€™s location?

Figure e16.34

4.50 m-