Floating and sinking. In this photo a wooden (oak) cylinder is floating but a nylon cylinder of the same size has sunk to the bottom of a tank filled with water. The upward buoyancy force on an object immersed in a fluid is equal to the weight of the displaced fluid (Archimedes' principle). It follows then that depending on the density of a solid object relative to the density of a liquid (such as water) the object will either sink in or float on the surface.
Model release not required. Property release not required.