What substance is a rectangular rod with a mass of m = 78 g made of, if its length is l = 0.5 cm.

What substance is a rectangular rod with a mass of m = 78 g made of, if its length is l = 0.5 cm. Width is b = 2.0 cm. height h = 1.0 dm.

The density of the substance from which the rod is made can be calculated using the formula:
ρ = m / V, where m is the mass of the rod (m = 78 g = 0.078 kg), V is the volume of a rectangular rod (V = a * b * c, where a = 0.5 cm = 0.5 * 10 ^ – 2 m, b = 2 cm = 2 * 10 ^ -2 m, c = 1 dm = 0.1 m).
Let’s calculate the density of the desired substance:
ρ = m / V = 0.078 / ((0.5 * 10 ^ -2) * (2 * 10 ^ -2) * 0.1) = 7800 kg / m ^ 3.
From the table of material densities, we determine that the rod is made of steel.
Answer: The rectangular bar is made of steel.