A ship is sailing over an underwater cliff. The seabed at the foot of the cliff is horizontal. The ship’s sonar equipment records two distinct echoes when a single ultrasonic pulse is transmitted vertically downwards: one echo returns after 1.40s from the top edge of the cliff and the other returns after 2.20s from the seabed at the foot of the cliff. Take the speed of sound in sea water to be 1500m/s.
(i) Calculate the vertical distance from the ship to the top edge of the cliff.
(ii) Calculate the vertical distance from the ship to the seabed at the foot of the cliff.
(iii) Hence find the height of the underwater cliff.