How do submarine use Archimedes' principle?

Answer 1

Using Archimedes' Principle, it is clear that a change in mass of an object affects how much liquid has to be displaced. In submarines, this is controlled by ballast tanks which are found between the submarine's inner and outer hulls.. When the tanks are empty, the submarine has less mass and it floats like a normal ship. As water is allowed into the tanks, the mass of the submarine increases, the downward gravitational force on the submarine increases and the submarine begins to sink. Careful balancing of the water ballast enables the craft to stay at any chosen depth.