Question

An osprey's call is a distinct whistle at 2200 hz. an osprey calls while diving at you, to drive you away from her nest. you hear the call at 2300 hz. part a how fast is the osprey approaching? express your answer to two significant figures and include the appropriate units. v = request answer provide feedback diving

Answer 1

While the osprey is approaching, the frequency of his whistle is shifted according to the formula (Doppler effect)
$f' = \frac{v}{v-v_s} f$
where 
f is the original frequency of the whistle (2200 Hz)
f' is the apparent frequency (2300 Hz)
v is the speed of sound in air (340 m/s)
vs is the speed of the source (the osprey) moving towards the observer 

We can re-arrange the formula to find vs, the speed of the osprey relative to the observer:
$v_s = \frac{f'-f}{f'} v= \frac{2300 Hz-2200 Hz}{2300 Hz} (340 m/s)=15 m/s$
so, the osprey is approaching at 15 m/s.