JAMB - Physics (2014 - No. 23)
A boy receives the echo of his clap reflected by a nearby hill 0.8s later. How far is he from the hill? [ speed of sound in air = \(340ms^{-1}\)
528m
66m
136m
264m
Explication
Time for echo both ways = 0.8
Therefore time for echo in 1 way = 0.8/2 = 0.4
Distance = Speed x time
Distance = 340 x 0.4
Distance = 136m
Therefore time for echo in 1 way = 0.8/2 = 0.4
Distance = Speed x time
Distance = 340 x 0.4
Distance = 136m