A bat is flitting about in a cave, navigating via ultrasonic beeps. Assume that the sound emission frequency of the bat is 40 kHz. During one fast swoop directly toward a flat wall surface, the bat is moving at 0.03 times the speed of sound in air. What frequency does the bat hear reflected off the wall? | Learn NCERT solution | Education portal Class 11 Physics | Study online Unit-15 Waves



Q.27:- A bat is flitting about in a cave, navigating via ultrasonic beeps. Assume that the sound emission frequency of the bat is 40 kHz. During one fast swoop directly toward a flat wall surface, the bat is moving at 0.03 times the speed of sound in air. What frequency does the bat hear reflected off the wall?

 

Answer:-

Ultrasonic beep frequency emitted by the bat, ν = 40 kHz
Velocity of the bat, vb = 0.03 v
where, v = velocity of sound in air
The apparent frequency of the sound striking the wall is given as: