The crane lifts a load weighing 2000 kg to a height of 40 meters in 2 minutes. Determine the efficiency

The crane lifts a load weighing 2000 kg to a height of 40 meters in 2 minutes. Determine the efficiency of the crane if it consumes 10kW of power.

Data: t (time spent by the crane used) = 2 min (in SI t = 120 s); h (lifting height) = 40 m; m (cargo weight) = 2000 kg; Nk (power consumed by the crane, consumed power) = 10 kW (10 * 10 ^ 3 W).

Constants: g (acceleration due to gravity) ≈ 10 m / s2.

The efficiency of the crane used is calculated by the formula: η = Np / Nz = (ΔEp / t) / Nz = m * g * h / (Nz * t).

Let’s calculate: η = 2000 * 10 * 40 / (10 * 10 ^ 3 * 120) = 0.667 or 66.7%.

Answer: The efficiency is 66.7%.