A boy standing some distance from the foot of a tall clif...
A boy standing some distance from the foot of a tall cliff claps his hands and hears an echo 0.5s later. If the speed of sound is 340ms\(^{-1}\), how far is he from the cliff?
680m
170m
34m
85m
Correct answer is D
V = \(\frac{2d}{t}\)
v = 340ms\(^{-1}\)
t = 0.5s
d= ?
d = \(\frac{2d}{2} = \frac{340 \times 0.5}{2}\) = 85m