A block of cork, a block of wood, and a block of metal are all placed into 3
separate beakers of water. The block of cork floats on top of the water,
while the block of wood floats near the surface of the water, and the block
of metal sinks to the bottom. Determine if each block is less dense, about
the same density, or more dense than the water.

Whether or not a block floats inside water is dependent on its density. If it is floating, it means it has a lower density. If it is sinking, it means it has a higher density. If it has the same, it will be half under and half over.

Mathematically, specific gravity can be used to support this phenomenon.

[tex]RD = \frac{p_{substance} }{p_{reference} }[/tex]

*In this context, water is our reference and the blocks are our substances.

Since Boyancy force can be described [tex]W = p_{substance}gV_{reference}[/tex] (the weight of the fluid disperced), having a higher density p than the reference liquid inherently will cause a greater downwards force from gravity.