An observer standing between two cliffs fires a gun. He hears one echo after `1.5 s` and another after `3.5 s`. If the speed of sound is `340 m//s`, find.
(a) the distance of the observer from the first cliff and.
(b) distance between the cliffs.

Answer

(a) 255 m
(b) 850 m.

Explanation

Here, `t_1 = 1.5 s, t_2 = 3.5 s, v = 340 m//s`
(a) `d_1 = (vt_1)/(2) = (340 xx 1.5)/(2) = 255 m`
(b) `d_2 = (vt_2)/(2) = (340 xx 3.5)/(2) = 595 m`
distance between the two cliffs, `d = d_1 + d_2 = 255 m + 595 m = 850 m`.