Atraffic police is blowing a whistle of frequency 200 hz if the sound is reflected from an oncoming double decker bus (speed 30 km/hr). the number of beats hear

Atraffic police is blowing a whistle of frequency 200 Hz If the sound is reflected from an oncoming double decker bus (speed 30 km/hr). The number of beats heard by a stationary observer is (assume the velocity of sound 340 m/sec) O 10 O 20 Tin O 30 O AO Solution 12. The mumber of beats = 200 200 = 200- 4 50200 - 10 c V, 1224 30