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My memories of fluid mechanics are very rusty and therefore I was wondering if you could help me with this hypothetical problem. Let's say I want to generate very high hydrostatic pressures in a liquid (of order of 400 kbar). Would it be enough to do the following: take a rod weighting 1 ton and drop it through a narrow tube with cross sectional area of 2.5x10^-4 m2 from a height of 5m under free-fall, such that upon impact with the liquid at the bottom of the tube the velocity of the rod is 10 m/s. According to the impulse theorem, the force exerted by the falling rod on the liquid when its fall is suddenly stopped (e.g. by a crane) is F=m dV/dt, where m=1000 kg, dv is 10 m/s and dt is for example 1x10-3 s. After dividing the force by the cross-sectional area, the resulting pressure should be 4x10^10 Pa, or 400 kbar. Can you see anything wrong with this reasoning until here?

Also let's assume that I want to redistribute this 400 kbar pressure across a much larger area. Can I take advantage of Pascal's theorem and assume that the 400 kbar pressure generated inside the narrow tube will be redistributed equally across a larger area below the tube inlet?

Thanks you in advance.....

Gabriele