A speeding motorcyclist sees traffic jam ahead of him. He slows down to 36 km cdot H^(-1) . He finds that traffic has eased and a car moving ahead of him at 18 km cdot h^(-1)is honking at a frequency of 1392 Hz. If the speed of sound is 343 m cdot s^(-1), the frequency of the honk as heard by him will be

A speeding motorcyclist sees traffic jam ahead of him. He slows down t

1.	A speeding motorcyclist sees traffic jam ahead of him. He slows down to 36 km cdot H^(-1) . He finds that traffic has eased and a car moving ahead of him at 18 km cdot h^(-1)is honking at a frequency of 1392 Hz. If the speed of sound is 343 m cdot s^(-1), the frequency of the honk as heard by him will be
Answer» 1332 HZ 1372 Hz 1412 Hz 1454 Hz Solution :Speed of motorcyclist, `u_(o)=36" KM" cdot h^(-1)=10m cdot s^(-1)` Speed of car, `u_(s)=18" km" cdot h^(-1)=5M cdot s^(-1)` Now, fundamental frequency of honk, v = 1392 Hz `therefore lambda. = (V+u_(s))/n=(343+5)/1392=0.25 m ` Hence, frequency of honk as heard by the cyclist `(V+V_(0))/(lambda.)=(343+10)/0.25=1412` Hz The option (c) is correct.