Many, many years ago, Archimedes was given a challenge to determine whether or not the king had been cheated by the goldsmith who had been commissioned to make his crown. The king suspected that the goldsmith had not used 24k gold. For a clever TED-ed animated 3 minute video of the principle, click here.
Archimedes principal indicates that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially submerged, is equal to the weight of the fluid that the body displaces. Our clear plastic tube with a metric scale directly affixed is used to demonstrate this principle.
A reading on the tube as it floats in water is taken before and after a known weight has been added.
By measuring the diameter of the tube, the volume as well as the weight of the displaced water can be calculated and compared to the known weight that was added.
Diameter: 2.5 cm