Question

A child hears an echo from a cliff 4 seconds after the sound from a powerful
cracher is produced, How far away is the cliff from the child? Given that the speed
of sound is 340
m/s.​

Answer 1

$\large \mathbb {GIVEN}$

$\footnotesize \rm \bold{time \: taken \: by \: sound \: to \: travel \: from \: child \: to \: cliff}$

$\rm \bold{ \: \: \: \: \: \: \: \: \: \: \: \: \: \: t = \frac{4}{2} = 2s}$

$\footnotesize \rm \bold{speed \: of \: sound \: in \: air : } \\ \rm \bold{v = 340 \:m/s }$

$\footnotesize \rm \bold{diatance \: of \: cliff \: from \: child = speed(v) \times time(t)}$

$\rm \bold{340 \times 2} \: m$

$\rm \bold{ \rightarrow \: 680 \: m} \: \: \: \rm{ans}$