Question

A person clapped his hand near a cliff and heard the echo after 5s. What is the distance of the cliff from the person if the speed of the sound, u is taken as 346ms^-1 ​

Answer 1

$\bold{\huge{\underline{Answer-}}}$

865m

$\bold{\huge{\underline{\underline{Solution}}}}$

Given,

$\sf \: Speed \: of \: sound \: u \: = 346m {s}^{ - 1} \\ \\ \sf \: Time \: taken \: to \: hearing \: the \: echo \: t \: = 5s \\ \\ \sf \: Distance \: travelled \: by \: the \: sound \: \\ \\ \implies \sf \: u \times t \\ \\ \implies \sf \: 346ms {}^{ - 1} \times 5s \: \\ \\ \implies \sf \: 1730m$

In 5s sound has to travel twice the distance between the cliff and the person . Hence , the distance between the cliff and person

= 1730m/2

= 865m

Answer 2

$\mathfrak{\huge{\red{\underline{\underline{Answer}}}}}$

Given,

speed of sound,

$v = 346 \: m \: s^{ - 1}$

Time taken for hearing the echo,

$t = 5 \: s$

Distance travelled by the sound

$= v \times t = 346m \: s^{ - 1} \times 5 \: s \: = 1730 \:m$

In 5 s sound has to travel twice the distance between the cliff and the persos. Hence,the distance between the cliff and the person.

$= 1730 \: m/2=865 \: m$

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