A police siren of frequency fsiren is attached to a vibrating platform. The platform and siren oscillate up and down in simple harmonic motion with amplitude Ap and frequency fp. Use v for the speed of sound. Part A Find the maximum sound frequency that you would hear at a position directly above the siren. At what point in the motion of the platform is the minimum frequency heard

he maximum frequency occurs when the denominator is minimum

 f’= f₀  

Explanation:

This is a doppler effect exercise, where the sound source is moving

           f = fo      when the source moves towards the observer

           f ’=f_o    Alexandrian source of the observer

the maximum frequency occurs when the denominator is minimum, for both it is the point of maximum approach of the two objects

          f’= f₀  

the results is a decrease in air temperature with an increase of altitude.

explanation:

the answer is a. hope this .