The crane lifted a reinforced concrete slab with a volume of 0.5 cubic meters in 20 seconds.

The crane lifted a reinforced concrete slab with a volume of 0.5 cubic meters in 20 seconds. What power did the crane move? density of reinforced concrete 2800 kg / m3.

Initial data: V (volume of the raised reinforced concrete slab) = 0.5 m3; t (duration of lifting the plate) = 20 s; h (conditional lifting height of the slab (not specified in the condition)) = 10 m.

Reference values: ρ (density of reinforced concrete) = 2800 kg / m3; g (acceleration due to gravity) ≈ 10 m / s2.

The power developed by the crane engine is calculated by the formula: N = A / t = ΔEp / t = m * g * h / t = ρ * V * g * h / t.

Let’s make the calculation: N = 2800 * 0.5 * 10 * 10/20 = 7000 W (7 kW).