Question

at what speed should a source of sound move away from a stationary observer so that observer finds the apparent frequency equal to half of the original frequency.

Answer 1

QuesTion :-

At what speed should a source of sound move away from a stationary observer so that observer finds the apparent frequency equal to half of the original frequency ?

SoluTion :-

$\rm {Frequency \ n'=\frac{n}{2}}\\\\\\\sf {\frac{n}{2}=n(\frac{v}{v+v_{s}} ) }\\\\\\\sf {\Rightarrow \frac{v+v_{s}}{v} =2}\\\\\\\sf {v_{s}=v}$