How long does it take for a 0.2 kW motor to perform 8 kJ work?

Engine power can be calculated using the formula:
N = A / t, where N is the engine power (N = 0.2 kW = 0.2 * 10 ^ 3 W), A is the mechanical work performed by the engine (A = 8 kJ = 8 * 10 ^ 3 J), t – engine running time (s).
Let us express and calculate the engine running time:
t = A / N = (8 * 10 ^ 3) / (0.2 * 10 ^ 3) = 40 s.
Answer: The engine running time is 40 s.