Can non quasi static process draw a curve on P-V image

Can non quasi static process draw a curve on P-V image

I don't quite understand what you mean
The P-V image only shows the pressure volume relationship. As long as the system can be represented by these two parameters, the P-V curve can be drawn, and it has nothing to do with whether it is a quasi-static process. For example, the diffusion of gas from a frictionless piston to a vacuum is absolutely numerous in textbooks

Calculation of buoyancy in Physics
When the submarine floats on the sea, the mass of the sea water discharged is 2500 tons, and the displacement of the submarine is 3200 tons. What is the volume of the water when it floats on the water? How many tons of sea water does it need to absorb in order to make it dive? (psea = 1.03 times 10 cubic kg / m3)

1. According to the buoyancy formula, f = PGV (P is the density), that is, the buoyancy is equal to the gravity of the drained water
In water, F1 = pgv1 = G1
At the surface, F2 = pgv2 = G2
V1 is the total volume of the submarine, V2 is the volume of the submarine floating in the water, then the volume of the part above the water
v3=v1-v2
G1 is the gravity of drained water in shallow water, G2 is the gravity of drained water in surface water
G1=m1g,G2=m2g
So V3 = V1-V2 = G1 / pg-g2 / PG = m1g / pg-m2g / PG = M1 / p-m2 / P = 679.61m3
2. To submerge is to submerge all the above water volume into the water. The above water volume will drain water and receive buoyancy. The buoyancy must be equal to the gravity of the water. Therefore, the mass of the water that needs to be flushed is m
Mg = pgv3, i.e. M = pv3 = 1.03 × 10 ^ 3 × 679.61 = 700000kg = 700ton
It can also be considered that the displacement difference between shallow water and floating water is 700 tons, which means that the buoyancy is so different from the gravity of water. In order to balance the buoyancy, so much water must be added and directly subtracted!
Responders

How to calculate buoyancy!
When an object floats on the water surface, the teacher said "when the upper surface does not touch the water, f floats = g object". However, shouldn't there be atmospheric pressure on the upper surface? Won't there be a downward force on the object? Don't you need to subtract the atmospheric pressure?

It is a fact that solids transfer pressure, while gases and liquids transfer pressure
And then to answer your question, because there is atmospheric pressure on the upper surface of the object, there is indeed a downward force, exactly pressure, but it does not need to be considered in the actual calculation, because we know that the surface of the water is also subject to atmospheric pressure, and this pressure is also transmitted to all surfaces of the object immersed in water through water
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