A mass of 18 kg has density 900 kg/m^3. What is its volume?

• A. 0.012 m^3
• B. 0.02 m^3
• C. 0.22 m^3
• D. 0.20 m^3

Answer: (B)

Volume comes from the relationship density = mass/volume, so volume = mass ÷ density. With a mass of 18 kg and a density of 900 kg/m^3, the volume is 18 ÷ 900 = 0.02 m^3. This value makes sense since the density is close to that of water, and 0.02 m^3 equals about 20 liters, which aligns with a mass of 18 kg at that density. If you plug the other volumes back into density = mass/volume, you’d get densities that don’t match 900 kg/m^3, which helps explain why they aren’t correct.