A submarine emits a sonar pulse, which returns from underwater cliff in 1.02 s. If the speed of sound in salt water is `1531ms^-1` how far away is the cliff ?

Explanation

Time between transmission and detection, t= 1.02s. Speed of ultrasound in sea water (salt water), `V=1531 ms^(-1)`. Distance travelled by the sonar pulse
`=2 xx` Depth of the sea
`=2 xx d`
where d= depth of the sea. Distance = Speed `xx` Time
`rArr 2d= V xx t`
`rArr 2d = 1531 ms^(-1) xx 1.02s`
`rArr 2d= 1561.62m`
`rArr d= (1561.62m)/(2)`
`rArr d= 780.81m`
Thus, the distance of the cliff from the submarine is 780.81 m or 0.781 km.