Determine the useful power of the crane, knowing that it lifts a load weighing 2 tons to a height of 9 m for 1 minute.

The useful power of the crane is calculated by the formula:
P = A / t, where A is the useful work of the crane (A = Fd * h, where Fd is the acting force (Fd = Ft = m * g, where m is the mass of the load (m = 2 t = 2000 kg), g is the acceleration of gravity (g = 10 m / s ^ 2)), h is the height to which the load was lifted (h = 9 m)), t is the operating time of the crane (t = 1 min = 60 s).
Let’s calculate the net power of the crane:
P = A / t = m * g * h / t = 2000 * 10 * 9/60 = 3000 W = 3 kW.
Answer: The net power of the crane is 3 kW.