What is the minimum distance required to hear an echo?
A. 10 meters
B. 13 meters
C. 17 meters
D. 21 meters
Answer
Correct Answer: C. 17 meters
Detailed About MCQs
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 the echo to be perceived by a person located at the source.