Final answer:
Density is the mass per unit volume of a substance, crucial for determining buoyancy in fluids. It is calculated by dividing the substance's mass by its volume. For a cubical object, measure the mass and the volume (by cubing the edge length) and then divide mass by volume.
Step-by-step explanation:
Density is an important characteristic of substances and is defined as the mass per unit volume of a substance or object. It plays a crucial role in phenomena such as whether an object will sink or float in a fluid. The equation to calculate density is ρ (rho) = m/V, where ρ is the symbol for density, m is the mass, and V is the volume occupied by the substance. Gases tend to be less dense than solids or liquids, and materials in either solid or liquid state can exhibit a range of densities.
To calculate the density of a substance, you divide its mass by its volume. For example, if you have a cube and you want to find its density, you would first measure its mass, then calculate its volume by cubing the edge length, and finally divide the mass by the volume you just calculated.