A man standing between two parallel cliffs fires a gun. If he hears the first echo after 2s and the next after 5s, the distance between the two cliffs is (Velocity of sound in air is 350 m/s)

Options

A. 1225 m
B. 1050 m
C. 2100 m
D. 2450 m

Answer

A

Explanation

`2(x_(1) + x_(2)) = v(t_(1) + t_(2))`
`x_(1) + x_(2) = (v)/(2) (t_(1) + t_(1))`
`= (350)/(2) (2 + 5)`
`= (350 xx 7)/(2) = (2450)/(2) = 1225m`