A wide container holds two immiscible fluids. The upper layer is engine oil of density 0.80×103kg m−3 to a depth of 20cm, and the lower layer is water of density 1.00×103kg m−3 to a depth of 30cm. Atmospheric pressure at the free surface is 1.0×105Pa.
(i) Starting from fundamental principles, obtain an expression for the pressure at the bottom of the container in terms of the individual fluid depths and densities.
(ii) Using the data given, calculate the absolute pressure at the bottom surface.
(iii) Determine the depth of an equivalent single column of water that would exert the same pressure as the two-layer arrangement above.