A sound of frequency 1500 Hz is emitted by a source which moves away from an observer and moves towards a cliff at a speed of 6 `ms^(-1)`
(a) Calculate the frequency of the sound which is coming directly from the source.
(b) Compute the frequency ofsound heard by the observer reflected off the cliff. Assume the speed of sound in air is 330 `ms^(-1)`

Options

A. 97 Hz
B. 100 Hz
C. 103 Hz
D. 106 Hz

Answer

C

Explanation

`f. = (v)/(v - v_(s) cos theta) = (330)/(330 - 19.4 cos 60^(@)) xx 100 = 103 Hz`