A tank contains a pool of mercury 0.3 m deep, covered with a layer of water that is 1.2 m deep. The density of water is 1.0 x 10^3 kg/m3 and that of mercury is 13.6 x 10^3 kg/m3. Find the pressure exerted by the double layer of liquids at the bottom of the tank. Ignore the pressure of the atmosphere. Please help me :(( and another one: In a partially submerged but floating object example a boat on a lake, what is the magnitude of the buoyant force? Why would it have this value?