Question

Mercury (density 13500 kg/m^3) is poured into a hollow glass cylinder of radius 5.00 cm to a depth of 15.0 cm. Water (density 1000. kg/m3) is then poured in on top of the mercury so that there is 20.0 cm of water on top of the mercury. What is the pressure at the bottom of the cylinder?

Answer 1

P = ρ g H pressure due to liquid of density ρ and height H

P = g (ρ1 H1 + ρ2 H2)

P = 9.80 m/s^2 (.15 m * 13500 kg/m^2 + .2 m * 1000 kg/m^2)

P = 9.80 m/s^2 (2025 + 200) kg/m^2 = 9.80 * 2225 kg / m s^2

P = 21,800 N/m^2

Note 1 N = (kg m / s^2)