Three characteristics that are unique to mammals include their  ability to feed their babies with milk made in their mammary  glands. Mammals also have hair on their bodies â¦and they have a  single bone that makes up their lower jaw.
buoyancy. n. 1. the ability to float in a liquid or to rise in a fluid. 2. (General Physics) the property of a fluid to exert an upward force (upthrust) on a body that is wholly or partly submerged in it. 3. the ability to recover quickly after setbacks; resilience.
If you mean the fact that the buoyant force is the weight of the displaced fluid, you're looking for the derivation of an (mg) term, not a volume. There is an article at this site that shows the derivation, on the following page: The derivation on that page makes the volume a cube, which isn't necessary.