A source of sound is travelling towards a stationary observer. The frequency of sound heard by the observer is of three times the original frequency. The velocity of sound is v m / sec . The speed of source will be

Options

A. `(2)/(3)v`
B. v
C. `(3)/(2) v`
D. 3v

Answer

A

Explanation

`n'=n((v)/(v-v_(s)))`
`rArr(n')/(n)=(v)/(v-v_(s))=3`
`rArrv_(s)=(2v)/(3)`