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

Speed of SONAR waves in water c = `1500 ms^(-1)`
Time taken to reflect from the bottom of the sea, 2t= 3.5 sec
`t = 1.75` sec
Distance covered in forward and reflected backward `(d_(1)) = c xx t`
`d_(2) = 1500 xx 1.75 = 2625` m
After ship moves in a distance = 150 km
Time taken to reflect by the waves 2t = 2s
t = 1 s
Distance covered by the waves `(d_2) = c xx t = 1500 xx 1 = 1500` m
The different between the height of two cases `= 2625 - 1500`
`h_("difference") = 1124` m