1. The problem statement, all variables and given/known data A rectangular wooden block of weight W floats with exactly one-half of its volume below the waterline. Masses are stacked on top of the block until the top of the block is level with the waterline. This requires 20g of mass. What is the mass of the wooden block? 2. Relevant equations Buoyant Force: F_b = (p_f)(V_f)(g) = w_o = (p_o)(V_o)(g) Mass Density: m = pV 3. The attempt at a solution Since the block is initially half submerged, its density is one-half of the water: p_o = 0.50g/cm^3 I'm assuming that the density of the block and the density of the fluid don't change. Without the volume, I don't see how to use the formulas... My only guess at the answer is 40g because it would require 20g to overcome the initial buoyant force (where the block floats halfway submerged)?