Density is defined as mass per unit volume and is commonly expressed in which unit?

Density is defined as mass per unit volume and is commonly expressed in which unit?

• A. Meters per kilogram
• B. Pounds per cubic foot
• C. Newtons per liter
• D. Gallons per cubic meter

Answer: (B)

Density is mass per unit volume, so its units express how much mass fits into a given volume. In the US customary system, the common density unit is pounds per cubic foot, which directly shows how many pounds of mass occupy each cubic foot of space. The other options don’t fit because they either invert the relationship (meters per kilogram is volume per mass, not density), mix in a force unit (newtons per liter combines force with volume), or represent volume per volume (gallons per cubic meter is a volume-to-volume ratio, not mass per volume). So pounds per cubic foot is the standard way to express density in many HVAC contexts.

Density is mass per unit volume, so its units express how much mass fits into a given volume. In the US customary system, the common density unit is pounds per cubic foot, which directly shows how many pounds of mass occupy each cubic foot of space.

The other options don’t fit because they either invert the relationship (meters per kilogram is volume per mass, not density), mix in a force unit (newtons per liter combines force with volume), or represent volume per volume (gallons per cubic meter is a volume-to-volume ratio, not mass per volume).

So pounds per cubic foot is the standard way to express density in many HVAC contexts.