Question

A bat at rest sends out ultrasonic sound waves at 50.0 kHz and receives them returned from an object moving directly away from it at 27.5 m/s. What is the received sound frequency?

Answer 1

Answer:

f = 42.5 kHz

Explanation:

Frequency of the sound due to reflection of an object moving away from the bat is given as

$f = f_0(\frac{v - v_o}{v + v_o})$

here we know that

$v_o = 27.5 m/s$

v = 340 m/s

also we know that

$f_o = 50 kHz$

now we will have

$f = (50 kHz) (\frac{340 - 27.5}{340 + 27.5})$

$f = 42.5 kHz$

so the sound frequency received from the object is 42.5 kHz