A boy stands 83 m in front of a high wall and then blows a whistle, calculate the time interval when he hears an echo. Speed of sound is 332 m/s.

A boy stands 83 m in front of a high wall and then blows a whistle, ca

1.	A boy stands 83 m in front of a high wall and then blows a whistle, calculate the time interval when he hears an echo. Speed of sound is 332 m/s.
A.	2.0 s
B.	0.5 s
C.	1.0 s
D.	2.5 s
Answer» C. 1.0 s