A piece of wood is 6.00m long, 0.250m wide and 0.080m thick. Its density is 600kg/m cubed. what volume of iron ( P iron = 7.8 x 10 cubed kg/m cubed) must be fastened underneath the wood to sink it so that the top surface of the wood is just even with the water (P water = 1.00 x 10 cubed kg/m cubed) level?