Question

Two sound sources are moving away from a stationary observer in opposite direction with velocities `V_1` and `V_2(V_1gtV_2)`. The frequency of both the sources is 900 Hz. `V_1` and `V_2` are both quite less than speed of sound, `V=300(m)/(s)`. Find the value of `(V_1-V_2)` so that beat frequency observed by observer is 9 Hz. (in m/s).

Answer 1

`f_1=900((300)/(300+V_1))`
or `f_1=900[1+(V_1)/(300)^-1]=900-3V_1`
Likewise, `f_2=900-3V_2`
given `f_2-f_1=9impliesV_1-V_2=3(m)/(s)`