How far from a cliff should a boy stand in order to hear the echo of his clap 0.9s later? (Speed of sound in air = 330 m/s)

A. 36.67m
B. 74.25m
C. 148.50m
D. 297.00
E. 366.67m

Correct Answer:

Option C – 148.50m

Explanation

v = 2x/t ∴ distance x = vt/2 = 148.5m