A factory whistle emits sound of frequency 570 Hz. When the wind velocity is 12.0 m/s from

Question:

A factory whistle emits sound of frequency 570 Hz. When the wind velocity is 12.0 m/s from the north, what frequency will observers hear who are located, at rests.
(a) Due north,
(b) Due South
(c) Due east, and
(d) Due west, of the whistle? What frequency is heard by a cyclist heading
(e) North of
(f) West, toward the whistle at 15.0m/s? Assume T = 20oC.