The siren of a police car atrest emits a predominant frequency of 1600 Hz and the police car isovertaking you from the rear, at a speed of 200 km/h. You areproceeding in the same direction at 50 km/h.
a. What frequency do you hear initially?
b. What frequency will you hear,when the police car passes you and continues on at 150 km/h afteryou have slowed to 25 km/h to insure you don't get in the way?