A band playing music at a frequency `f` is moving towards a wall at a speed `v_(b)`. A motorist is following the band with a speed `v_(m)`. If `v` is the speed of sound, obtain an expression for the beat frequency heard by the motorist.

Options

A. `((v+v_(m))f)/(v+v_(0))`
B. `((v+v_(m))f)/(v-v_(0))`
C. `(2v_(0)(v+v_(m))f)/(v^(2)-v_(0)^(2))`
D. `(2v_(m)(v+v_(b))f)/(v^(2)-v_(b)^(2))`

Answer

C