(a) State Pascal’s principle.
(b) A vertical tube is filled with an incompressible liquid of density ρ. The pressure at the free surface is the atmospheric pressure p0. Derive an expression for the pressure p at a depth h below the free surface.
(c) Explain, without substituting numerical values, how you would obtain the depth of a point inside the liquid if only the gauge pressure Δp=p−p0 and the density ρ of the liquid are known.