How is density defined?

How is density defined?

• A. Density is mass per unit volume.
• B. Density is volume per unit mass.
• C. Density is energy per volume.
• D. Density is temperature per mass.

Answer: (D)

Density measures how much matter is packed into a given space. It is defined as mass per unit volume, or density = mass ÷ volume. In units, mass is usually in kilograms and volume in cubic meters in the SI system, giving kg/m^3, but for everyday substances we often use g/cm^3. For example, if a block has a mass of 200 g and a volume of 100 cm^3, its density is 2 g/cm^3. The other ideas don’t describe density. Volume per mass would be the reciprocal of density and describes how large a space each unit of mass occupies, not density. Energy per volume is energy density, a different concept. Temperature per mass isn’t a defined density.

Density measures how much matter is packed into a given space. It is defined as mass per unit volume, or density = mass ÷ volume.

In units, mass is usually in kilograms and volume in cubic meters in the SI system, giving kg/m^3, but for everyday substances we often use g/cm^3. For example, if a block has a mass of 200 g and a volume of 100 cm^3, its density is 2 g/cm^3.

The other ideas don’t describe density. Volume per mass would be the reciprocal of density and describes how large a space each unit of mass occupies, not density. Energy per volume is energy density, a different concept. Temperature per mass isn’t a defined density.