What is Density?

What is Density?

• A. Its mass per unit volume.
• B. Its volume per unit mass.
• C. Its weight per unit volume.
• D. Its mass per weight.

Answer: (C)

Density measures how much matter is packed into a given volume. It is defined as mass divided by volume: ρ = m / V. This quantity describes the material itself and does not depend on gravity. Weight per unit volume would be weight density, which equals mass density times the local gravitational acceleration, and that varies with gravity. So the standard density is mass per unit volume. For example, a cubic meter of lead has a much larger density than a cubic meter of air because it contains far more mass in the same space.

Density measures how much matter is packed into a given volume. It is defined as mass divided by volume: ρ = m / V. This quantity describes the material itself and does not depend on gravity. Weight per unit volume would be weight density, which equals mass density times the local gravitational acceleration, and that varies with gravity. So the standard density is mass per unit volume. For example, a cubic meter of lead has a much larger density than a cubic meter of air because it contains far more mass in the same space.