A ship in a sea sends SONAR waves straight down into the seawater from the bottom of the ship. The signal reflects from the deep bottom bed rock and returns to the ship after 3.5 s. After the ship moves to 100 Km it sends another signal which returns back after 2s. Calculate the depth of the sea in each case and also compute the difference in height between two cases.

Explanation

In first case
time 3.5s
Velocity sound in sea water=1450 m/s
Distance `2d=vxxt`
`=1450xx3.5=5,075m`
Depth of the sea `d=(5075)/(2)=2537.5m`
In the second case,
time 2s
Velocity of sound in water =1450 m/s
Distance 2d=vt
`=1450xx2`
=2900 m
Depth of sea `d=(2900)/(2)=1450`
Difference3 `Deltad=2537.5-1450=1087.5`
`=1087.5`m