Final answer:
When a metal pin and a piece of wood of the same mass are dropped into water, the metal pin sinks due to its higher density, while the wood floats because its density is lower than that of water. This outcome is explained by density and Archimedes' Principle, which relates to buoyant forces and displaced water.
Step-by-step explanation:
If you drop a piece of metal pin and a piece of wood of the same mass into the water, different things will happen due to the concept of density. Density is the mass of a material per unit volume. Considering a metal pin and a block of wood with equal masses, the metal pin will sink because it has a higher density than water. On the other hand, the wood will generally float since it typically has a lower density than water. This phenomenon is also related to Archimedes' Principle, which states that an object submerged in a fluid is acted upon by an upward, or buoyant, force equal to the weight of the fluid displaced by the object. The metal pin, being denser than water, displaces a volume of water less than its weight, and therefore it sinks. The wood, with a lower density, displaces water equal to or more than its weight, allowing it to float.
This can be further illustrated with the example of molding clay. A lump of clay will sink because it cannot displace enough water to counteract its weight. However, if you mold the clay into the shape of a boat, it will float because the shape allows it to displace more water, thus experiencing a greater buoyant force.