Question

while hunting in a cave a bat emits sounds wave of frequency 39 kilo hartz were moving towards a wall with a constant velocity of 8,32 meters per second take the speed of sound as 340 meters per second calculate frequency​

Answer 1

Complete question:

while hunting in a cave a bat emits sounds wave of frequency 39 kilo hartz were moving towards a wall with a constant velocity of 8.32 meters per second take the speed of sound as 340 meters per second. calculate the frequency​ reflected off the wall to the bat?

Answer:

The frequency reflected by the stationary wall to the bat is 41 kHz

Step-by-step explanation:

Given;

frequency emitted by the bat, f = 39 kHz

velocity of the bat,
`v_b` = 8.32 m/s

speed of sound in air, v = 340 m/s

Apply the doppler-effect principle to solve this problem.

The apparent frequency of sound striking the wall is calculated as;

`f' = f((v)/(v- v_b) )\\\\f' = 39,000((340)/(340 -8.32) )\\\\f' = 39978.29 \ Hz`

The frequency reflected by the stationary wall to the bat is calculated as;

`f_s = f'((v + v_b)/(v) )\\\\f_s = 39978.29((340 + 8.32)/(340) )\\\\f_s = 40,956.56 \ Hz`

`f_s\approx 41 \ kHz`