A block of concrete is 1m long, 50cm wide and 4cm thick. Calculate the volume of the block in cm^3. If 1cm^3 has a mass of 2.7g, find the mass of the block in kg.

Answer 1

Volume of the block = length x width x thickness
= 100cm x 50cm x 4cm
= 20,000 cm^3

Mass of the block = volume x density
Density of concrete is typically around 2,400 kg/m^3 or 2.4 g/cm^3.

Therefore, the mass of the block would be:
20,000 cm^3 x 2.4 g/cm^3 = 48,000 g
1 kg = 1000 g, so the mass of the block in kg would be:
48,000 g ÷ 1000 = 48 kg

Answer: The volume of the block is 20,000 cm^3 and the mass of the block is 48 kg.

Answer 2

Student said the density is 2.7 g/cm^3

Answer 3

If the student dismissed the typical density of concrete and used a density value of 2.7 g/cm^3, then the mass of the block should be recalculated:

Volume of the block = length x width x thickness
= 100cm x 50cm x 4cm
= 20,000 cm^3

Mass of the block = volume x density
= 20,000 cm^3 x 2.7 g/cm^3
= 54,000 g

To get the mass of the block in kg:

54,000 g ÷ 1000 = 54 kg

Therefore, if the density of the concrete used by the student is 2.7 g/cm^3, then the mass of the concrete block is 54 kg.