A person standing on an open ground hears the sound of a jet aeroplane , coming from north at an angle `60^(@)` with ground level ,But he finds the aeroplane right vertically above his position , if V is the speed of sound , speed of the plane is :

Options

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

Answer

A

Explanation

`(d)/(v_(Sound))= (d cos 60)/(Va)`
`V_(aeroplane)= (V_(Sound))/(2)`