Answer:
The bottom of the sea is 25 m below sea level.
Explanation:
Given data
Mass = 6.1 × 

We know that Buoyant force on the tank is equal to gravity force of the tank.



1020 ×
= 6.1 × 
= 598039.21 
We know that
= W × L × H
598039.21 = 300 × 80 × H
H = 25 m
Therefore the bottom of the sea is 25 m below sea level.
<span>Submarines are equipped with water tanks called ballast tanks that fill up to submerge the vessel. Emptying the tanks and filling them with air causes the submarine to surface.</span>
The acceleration can be found by:

Where v= velocity and t= time
or