The echo (reflected sounD. will be distinctly heard only at ordinary temperatures if the distance of the reflecting surfaces from the source of sound is at least ________...?
(A) 1120 ft
(B) 120 ft
(C) 56 ft
(D) 100 ft
✅ Correct Answer:56 ft
Comments
The echo (reflected sounD. will be distinctly heard only at ordinary temperatures if the distance of the reflecting surfaces from the source of sound is at least ________...?