A pine log with a diameter of 25 cm is 60 cm long. What is the weight of the log?

Initial data: D (diameter of a pine log) = 25 cm (0.25 m); L (length of a pine log) = 60 cm (0.6 m).

Reference data: ρс (average density of pine) = 520 kg / m3.

The mass of a pine log can be determined by the formula: m = ρс * V = ρс * S * L = ρс * 0.25 * Π * D ^ 2 * L.

Let’s calculate: m = 520 * 0.25 * 3.14 * 0.25 ^ 2 * 0.6 ≈ 15.3 kg.

Answer: The mass of a pine log is 15.3 kg.