What work does a 10 kW motor do in 30 minutes?

Engine power can be calculated using the formula:
N = A / t, where N is the engine power (N = 10 kW = 10 * 10 ^ 3 W), A is the mechanical work performed by the engine (J), t is the engine operation time (t = 30 min = 30 * 60 s = 1800 s).
Let us express and calculate the useful work of the engine:
A = N * t = (10 * 10 ^ 3) * 1800 = 18,000,000 J = 18 * 10 ^ 6 J = 18 MJ.
Answer: The perfect work of the engine is 18 MJ.