A man is driving a car at a speed of 72 kmph towards a hill. He sounds the horn and hears its echo after 2 s. At what distance from the hill the horn was sounded. (Velocity of sound = `340 ms^(-1)`)

Options

A. 40 m
B. 340 m
C. 360 m
D. 380 m

Answer

C

Explanation

`v = 72 xx (5)/(18) = 20 m//s`
`v = (2x - 20 xx 2)/(t)`
`340 xx 2 = 2x - 40`
`680 + 40 = 2x`
`2x = 720`
`x = 360 m`