A man standing unsymmetrical position between two mountains and fires a gun. He hears the first echo after 1.5 s and the second echo after 2.5 s. If the speed of sound in air is 340 m/s, then the distance between the mountains will be

Options

A. 340 m
B. 410 m
C. 640 m
D. 680 m

Answer

D

Explanation

Let `x_(1)` bet the neareast distance between the person and mountain and `x_(2)` be the fartest distance between the person and mountain
`:. x_(1) + x_(2) = (v)/(2) (t_(1) + t_(2)) = (340)/(2) (2.5 + 1.5) = 680 m`