A boy standing a distance from the foot of a tall cliff claps his hands and hears an echo 0.5s later. If the speed of sound is 340ms1, how far is he from the cliff?
A
17m
B
34m
C
85m
D
170m
E
680m
Verified Correct Answer: C.
Physical Principles & Numerical Solution
X = vt/2 = (340 x 0.5)/2 = 85m
Source: Myschool Past Questions Archive (Record #21249)