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A solid cylinder stands vertically immersed across two immiscible liquids of densities rho (upper) and 2*rho (lower), each layer of height h around the cylinder. Find the pressure difference between a point A at the top of the upper liquid and a point B at the bottom of the lower liquid (separated vertically by the two layers).
- 2*rho*g*h
- 3*rho*g*h
- 4*rho*g*h
- None
Correct answer: 3*rho*g*h
Solution
Going from A (top) down to B (bottom) you cross a column of height h of density rho and then a column of height h of density 2*rho. The total gauge pressure increase is rho*g*h + 2*rho*g*h = 3*rho*g*h.
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