a) A cube of wood whose edge is 12 mm is floating in a liquid in a glass with one of its faces parallel to the liquid surface. The density of wood is 909 kg/m^3, that of liquid is 1296 kg/m^3. How far hL below the liquid surface is the bottom face of the cube?
b) A light oil is gently poured onto the immiscible liquid surface to form a 2.9 mm thick layer above the liquid. The density of the oil is 606 kg/m^3. When the wood cube attains hydrostatic equilibrium again, what will be the distance from the top of the liquid to the bottom face of the cube?
c) Additional light oil is poured onto the liquid surface until the top surface of the oil coincides with the top surface of the wood cube (in hydrostatic equilibrium). How thick is the whole layer of the light oil?