Question

A person standing between the two vertical cliffs produces a sound. Two successive echoes are heard at 4 s and 6 s. Calculate the distance between the cliffs.
(Speed of sound in air = 320 ms^-1)

Answer 1

Let distance of 1 ^st cliff = d₁m

t = 4 sec

Speed of sound in air V = 320 ms^-1

∴ d₁ = `(v xx t)/2`

= `(320 xx 4)/2`

= 640 m

For cliff II d₂  = `(v xx t)/2`

= `(320 xx 6)/2`

= 960 m

∴ Total distance between two cliff is 

d = d₁ + d₂ 

= 640 + 960

= 1600 m