Question

A man standing between two cliffs produces a sound and hears two successive echoes at intervals of 3s and 4s respectively. Calculate the distance between the two cliffs. The speed of sound in the air is 330 ms⁻¹.

Answer 1

∵ Ist echo is heard from the nearest cliff so let its distance be d₁
∴ d₁ = s × t = `330xx3/2` = 495 m and
 ∵ IInd echo is heard from the further cliff so let it be d₂
∴ d₂ = s × t = `330xx4/2` = 660 m
∴ Total distance = 660 + 495 = 1155 m.