3. Two speakers both produce sound wave ..-阿摩線上測驗
3. Two speakers both produce sound wave of power = 400πWatt, frequency = 170 Hz,
and sound velocity = 340 m/s. They act as point sources and propogate in all directions.
The output of the two speakers are synchronized and have the same phase. They are
placed at different locations and the distances between the speakers and the observer P
are d1 = 10 m and d2 = 5 m, respectively. What is the intensity of the sound wave
detected by the observer? (The effect of interference should be considered.)
(A) 1 W/m2
(B) 2 W/m2
(C) 3 W/m2
(D) 5 W/m2
(E) 9 W/m2