A crane with an engine with a power of 5 kW lifts the load evenly at a speed of 0.2 m / s. Determine the weight of the load.

N = 5 kW = 5000 W.

V = 0.2 m / s.

g = 10 m / s2.

m -?

Let us write out the crane power N according to the formula: Np = A / t, where Ap is the useful work of the crane, t is the time of work.

The useful work of crane A is that a load of mass m was lifted to a height h: A = m * g * h, where g is the acceleration of gravity.

The formula for determining the useful power of the crane Nп will take the form: N = m * g * h / t = m * g * V, since the ratio of the height h to the time of lifting the load t is the speed of its lifting V: V = h / t.

m = N / g * V.

m = 5000 W / 10 m / s2 * 0.2 m / s = 2500 kg.

Answer: the crane lifts a load with a mass of m = 2500 kg.