question 12 which of the following are appropriate units for density? lbs/sec^3 lb/ft^3 kg/m g/cm^2

Explanation:

Step1: Recall density formula

Density $\rho=\frac{m}{V}$, where $m$ is mass and $V$ is volume.

Step2: Analyze mass and volume units

Mass units can be lbs, lb, kg, g etc. Volume units are cubic - like $ft^{3}$, $m^{3}$, $cm^{3}$ etc.

Step3: Check each option

• lbs/sec³ has time unit in denominator, not volume, so incorrect.
• lb/ft³ has mass (lb) and volume ($ft^{3}$), correct.
• kg/m has length unit in denominator instead of volume, incorrect.
• g/cm² has area unit in denominator instead of volume, incorrect.

Answer:

lb/ft³