The efficiency of the heat engine is 30%. The working fluid received 5 kJ of heat from the heater.

The efficiency of the heat engine is 30%. The working fluid received 5 kJ of heat from the heater. Calculate the work done by the engine.

The efficiency of a heat engine can be expressed by the formula:
η = A / Q, η is the efficiency of the heat engine (η = 30% = 0.3), A is the value of the perfect work by the heat engine (J), Q is the energy expended by the heat engine (Q = 5 kJ = 5 * 10 ^ 3 J).
Let us express and calculate the work done by the heat engine:
A = η * Q = 0.3 * 5 * 10 ^ 3 = 1500 J = 1.5 kJ.
Answer: The work done by a heat engine is 1.5 kJ.