Question:
A bat emitting an ultrasonic wave of frequency $4.5 \times 10^{4} \mathrm{~Hz}$ flies at a speed of $6 \mathrm{~m} \mathrm{} \mathrm{s}^{-1}$ between two parallel walls. Find the fractional heard by the bat and the beat frequencies heard by the bat and the beat frequency between the two. The speed of sound is $330 \mathrm{~m} \mathrm{~s}^{-1}$.
Solution:
