Final answer:
To calculate the density of the steel bar, divide its mass (96g) by its volume (12 cm³), resulting in a density of 8 g/cm³. This supports the statement that rebar, known to be mostly iron, has a similar density.
Step-by-step explanation:
The density of an object is calculated by dividing its mass by its volume. The mass of the rectangular steel bar given is 96g, and its volume can be determined by multiplying its length by its width by its thickness: Volume = 4 cm x 3 cm x 1 cm = 12 cm³. To find the density, divide the mass by the volume, yielding: Density = 96g / 12 cm³ = 8 g/cm³.
Comparing this to known densities of materials, the calculated density is close to that of iron, which supports the notion that the steel bar is mostly iron, given that the density of iron is typically around 7.9 g/cm³. Therefore, the density calculation does support the statement that rebar, a steel construction material, is largely composed of iron.