1. The problem statement, all variables and given/known data A 6.40 cm-tall cylinder floats in water with its axis perpendicular to the surface. The length of the cylinder above water is 1.00cm. 2. Relevant equations What is the cylinder's mass density? 3. The attempt at a solution Well, I am confused because I can use the equation for buoyancy to find the mass of the cylinder, but I don't know how to find its volume.