WBCS.LIVE practice question

What is the minimum distance required between a source of sound and a reflecting surface to hear a distinct echo?

Solve this multiple-choice question and check the correct answer with its explanation below.

Answer options

  1. 17.2 meters
  2. 10.2 meters
  3. 34.4 meters
  4. 5.1 meters

Correct answer and explanation

Correct answer: 17.2 meters

Explanation: āœ… Correct Answer: A) 17.2 meters šŸ“š Explanation: To hear a distinct echo, the reflected sound must reach the ear at least 0.1 seconds after the original sound. Taking the speed of sound in air as approximately 344 m/s, the total distance traveled (to the wall and back) must be 34.4 meters. Therefore, the minimum distance from the observer to the wall must be half of that, which is 17.2 meters.