Displacement. Composite image showing stages of an experiment to show the concept of displacement by a floating object. At left is a container filled with water to the level of the spout. Next, a block of wood is lowered into the water. The block displaces water which flows out of the spout and is collected in a beaker. Finally, the mass of the water and the mass of the block can be measured to show that they are equal - a demonstration of Archimedes' principle.