Two Loudspeakers 6

Multiple Choice

Two loudspeakers 6.00 m apart emit the same frequency tone in phase at the speakers. A listener notices that the intensity of the sound is minimized when she is placed at A, 8.00 m in front of the second speaker. The listener starts walking toward the first speaker in a circle of radius 8.00 m until she reaches B, where she hears the first maximum. Assuming the speed of sound in air is 343 m/s, the length of the arc AB is

A) 12.3 m.
B) 9.23 m.
C) 6.15 m.
D) 3.08 m.
E) 1.58 m.