A source of sound which emitting a sound of frequency 600 Hz is moving towards a wall with a velocity 30 m/s. Three observes A, B, C moving with velocity 20 m/s, A away from the wall and B towards the wall and Inside the source, Velocity of sound in air is 330 m/s.

Find the frequency of direct sound observed by observer A

Options

A. `600 310/360` Hz
B. `600 210/360` Hz
C. `600 110/360` Hz
D. None of these

Explanation

Frequency of direct sound observed by observer A is
`f=f_0((vpmv_(0m))/(vpmv_(sm)))`
`f=600((330-20)/(330+30))=600 310/360` Hz