A cube of side length 2 m has mass 56 kg. What is its density?

A cube of side length 2 m has mass 56 kg. What is its density?

• A. 14 kg/m^3
• B. 7 kg/m^3
• C. 3.5 kg/m^3
• D. 28 kg/m^3

Answer: (B)

Density is how much mass is packed into a given volume. For a cube, volume = side length cubed. With a side of 2 m, the volume is 2^3 = 8 m^3. The mass is 56 kg, so density = 56 kg / 8 m^3 = 7 kg/m^3. The unit is kilograms per cubic meter. So the correct result is 7 kg/m^3.

Density is how much mass is packed into a given volume. For a cube, volume = side length cubed. With a side of 2 m, the volume is 2^3 = 8 m^3. The mass is 56 kg, so density = 56 kg / 8 m^3 = 7 kg/m^3. The unit is kilograms per cubic meter. So the correct result is 7 kg/m^3.