A siren emitting a sound of frequency 800 Hz moves away from an observer towards a cliff at a speed of 15 m cdot s^(-1). Then the frequency of sound that the observer hears in the echo reflected from the cliff is (take velocity of sound in air = 330 m cdot s^(-1))

A siren emitting a sound of frequency 800 Hz moves away from an observ

1.	A siren emitting a sound of frequency 800 Hz moves away from an observer towards a cliff at a speed of 15 m cdot s^(-1). Then the frequency of sound that the observer hears in the echo reflected from the cliff is (take velocity of sound in air = 330 m cdot s^(-1))
Answer» 800 Hz 838 Hz 885 Hz 765 Hz Solution :Apparent FREQUENCY of ECHO `n.=n(V/(v-v_(s)))=800(330/(330-15))` `=(800xx330)/315=838` Hz The option (B) is correct.