A small wooden cube floats in fresh water so that exactly 60 % of its volume remains below the water surface.
(i) Explain what the observed submerged fraction tells you about the density of the wood compared to the density of water.
(ii) The same cube is gently transferred to seawater of density 1030kgm−3. Will the fraction of the cube submerged increase, decrease or remain unchanged? Give a reason for your answer.
(iii) Without carrying out a numerical calculation, state whether the height of the cube that projects above the seawater surface will be greater than, less than, or equal to the height that projected above the freshwater surface. Justify your choice.