A bat moving with a speed of 3.10 m/s and emitting sound of 37.0 kHz approaches
ID: 1649647 • Letter: A
Question
A bat moving with a speed of 3.10 m/s and emitting sound of 37.0 kHz approaches a moth at rest on a tree trunk. What frequency is heard by the moth? I know the answer (37.3 kHz) I just don't understand how they got there please explain! A bat moving with a speed of 3.10 m/s and emitting sound of 37.0 kHz approaches a moth at rest on a tree trunk. What frequency is heard by the moth? I know the answer (37.3 kHz) I just don't understand how they got there please explain! I know the answer (37.3 kHz) I just don't understand how they got there please explain!Explanation / Answer
According to Doppler effect of sound, we know,
f = [(c + vr) / (c - vs)] fo
where vr and vs are speeds of receiver and source respectively and are positive if they move towards the other.
So,
f = [(340 + 0) / (340 - 3.10)] * 37 = 37.3 kHz