Question

What should be the minimum source for a distinct echo to the heart.

Answer 1

Answer: The velocity of sound in dry air is approximately 343 m/s at a temperature of 25 °C. Therefore, the reflecting object must be more than 17.2m from the sound source for echo to be perceived by a person located at the source. Answer: The minimum distance from reflector is 16.6 m.

Answer 2

17.2 metre from the source