Explain this in four sentences.

Question

Imagine you have just been selected to join a mission to board a submarine. Examine the forces you would experience both as you board the submarine and as you are onboard the submarine. In particular, what force pulls the submarine into the water? Once in the water, in which direction will the hydrostatic pressure be acting? Do you think you will have to pop your ears? What force will push up on you? Explain the buoyancy (positive, negative, neutral) and when the submarine might experience them.

Answer 1

As you board the submarine, you experience gravitational force pulling you downward, while buoyant forces act on the submarine once it is submerged. The force that pulls the submarine into the water is gravity, which works against the buoyant force when it is partially submerged. Once in the water, the hydrostatic pressure acts in all directions, but primarily upward due to the pressure from the water above, which increases with depth; you will likely need to pop your ears to equalize pressure changes. The submarine experiences buoyancy that can be positive (causing it to rise), negative (causing it to sink), or neutral (when it is submerged at a constant depth), depending on its relative density to the surrounding water and its ballast adjustments.