Question

What frequency is received by a stationary mouse just before being dispatched by a hawk flying at it at 24.7 m/s and emitting a screech of frequency 3400 Hz? Assume room temperature air.

Answer 1

Answer:

   f' = 3665.51 Hz

Explanation:

given,

speed of the hawk = 24.7 m/s

frequency of screech emitted by the hawk = 3400 Hz

speed of sound = 331 m/s

By Doppler's effect

$f' = (\dfrac{v}{v-v_s}})f$

f' is the frequency received by the mouse

v is the speed of the sound

v_s is the speed of the hawk

now,

$f' = \dfrac{341}{341-24.7}}\times 3400$

   f' = 1.078 x 3400

   f' = 3665.51 Hz

The frequency received by the stationary mouse is equal to 3665.51 Hz