Question

A person standing between two vertical cliffs produces a sound. Two successive echoes are heard at 4 s and 6 s. Calculate the distance between the cliffs.

Answer 1

LetA₁ andA₂ be the distances of the two cliffs from the man. then
2 A₁ =320 x 4=1280 ............ (i)
and, 2 A₂ = 320 x 6 = 1920 .............. (ii)
Adding (i) and (ii)
2 ( A₁ +A₂) = 3200
or, A₁ +A₂ = 1600m
`therefore` distance between the two cliffs= 1600 m