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 = 2dt
v = 340ms−1
t = 0.5s
d= ?
d = 2d2=340×0.52 = 85m