A source of sound and a detector are placed at the same place on ground At `t=0`, the source `S` is projected towards reflector with velocity `v_0` in vertical upward directon and reflector starts moving down with constant velocity `v_0` At `t-0`, the vertical separation between the reflector and source is `H((gtv_0^2)/(2g))`. The speed of sound in air is `v(gtgtv_0)`, Take `f_0` as the frequency of sound waves emitted by source. Based on above information answer the following questions.
Q. Frequency of sound waves emitted by source at `t=(v_0)/(2g)` is

Options

A. `f_0`
B. `f_0[(v)/(v)+(v_0)/(2)]`
C. `f_0[((v-v_0)/(2))^(2)/(v)]`
D. `f_0[(((v-v_0)/(2))/(v+v_0))/(2)]`

Answer

B

Explanation

Actual frequency emitted by source does not depend upon the velocity of source but frequency heard may change due to relative motion between the observer and the source.