Question

In which one of the following locations can a person hear the echo of a sound?A. At least 33.2 meters behind the reflecting surface

B. At least 16.6 meters in front of the reflecting surface
C. Less than 33.2 meters behind the reflecting surface
D. Less than 16.6 meters in front of the reflecting surface

Answer 1

The right answer is B. At least 16.6 meters in front...

The sound moves in the air at 340 m / s, and the ear can only hear the echo if it returns at least 1 / 10th after its emission, a distance of at least 16.6 meters (or 17 meters) with reflective surface.

Answer 2

The location in which a person is more likely to receive an echo of the soud being sent is at least 16.6. meters in front of the reflecting surface. Therefore, the answer is to this item is letter A. The speed of sound without any interference is only about 340 m/s traveling through the vibration of the media in which it passes through.