A copper bar weighing 2.67 kg has dimensions of 25 cm × 6 cm × 2 cm (a = 25 cm, b = 6 cm, c = 2 cm). Is there a void in it?

Data: m (mass of a copper bar) = 2.67 kg; a (length of copper bar) = 25 cm; b (width of a copper bar) = 6 cm; c (copper bar thickness) = 2 cm.

SI system: a = 25 cm = 0.25 m; b = 6 cm = 0.06 m; s = 2 cm = 0.02 m.

1) Let’s calculate the volume of a copper bar: V = a * b * c = 0.25 * 0.06 * 0.02 = 0.0003 m3.

2) Determine the density of the copper bar and compare it with the table value: ρ = m / V = 2.67 / 0.0003 = 8900 kg / m3.

Because the obtained value corresponds to the density of copper, then there are no voids in the copper bar.