Which unit is used for density in the material?

Which unit is used for density in the material?

• A. pounds mass/feet cubed
• B. kilograms per cubic meter
• C. pounds force per cubic foot
• D. grams per liter

Answer: (A)

Density is mass per unit volume, so the unit should express how much mass sits in a given volume. In US customary engineering practice, mass is measured in pounds mass and volume in cubic feet, yielding density in pounds mass per cubic foot. Using pounds force per cubic foot would be weight density, not mass density, since it uses weight (a force) rather than mass. Kilograms per cubic meter and grams per liter are valid density units in SI, with 1 g/L equal to 1 kg/m^3, but the material context here typically uses the imperial unit pounds mass per cubic foot.

Density is mass per unit volume, so the unit should express how much mass sits in a given volume. In US customary engineering practice, mass is measured in pounds mass and volume in cubic feet, yielding density in pounds mass per cubic foot. Using pounds force per cubic foot would be weight density, not mass density, since it uses weight (a force) rather than mass. Kilograms per cubic meter and grams per liter are valid density units in SI, with 1 g/L equal to 1 kg/m^3, but the material context here typically uses the imperial unit pounds mass per cubic foot.