an oceanic depth-sounding vessel surveys the ocean bottom width ultrasonic waves...

[Sam]

...that travel 1530 m/s in? seawater.
how deep is the water directly below the vessel if the time delay of the echo to the ocean floor and back 5 s?

 

[Sreeda]

given time (t) taken by wave to reach the ocean floor and back = 5s
velocity, v= 1530m/s
if the dist b/n the vessel n ocean floor is R, the total dist travelld by the wave is 2R.
we kno, velocity= distance travelld/time takn
substituting the givn data in the above eqn n solvin will give yu the answer.
i guess this should give you the ans.