The correct option is C 525 Hz
Given,
velocity of observer (vo)=30 m/s
velocity of source (vs)=12 m/s
velocity of sound in stationary air (v)=330 m/s
velocity of wind (vw)=8 m/s
When the source and observer are moving away from each other in a stationary medium, we can write,
fapp=f0(v−vov+vs)
When the medium is not stationary and velocity of medium is vw, actual velocity of sound with respect to the ground is given by v±vw
Thus, we can write that,
fapp=f0(v±vw−vov±vw+vs)
From the diagram, we can deduce that the direction of wind is from the observer to the source.
So, fapp=f0(v−vw−vov−vw+vs)
From the data given in the question,
fapp=600(330−8−30330−8+12)=600×292334≈525 Hz