A steam engine receives 300 kJ of heat from its environment and does 400 kJ of work. How much does the energy of the steam engine change? Physics Thermodynamics Heat and Work 1 Answer Junaid Mirza Nov 23, 2017 Energy of system is decreased by #"100 kilojoules"# Explanation: Form 1st law of thermodynamics #"dU = dQ + dW"# #"dU = 300 kJ + (-400 kJ)"# [Work is done by the steam engine. Hence i took -400 kJ] #"dU = -100 kJ"# Answer link Related questions How does heat energy affect the movement of water molecules? How does heat affect the movement of molecules? What is thermodynamics equilibrium? How can heat cause motion in a liquid? Is heat transferred in our atmosphere by conduction? How is heat energy transferred? How are energy heat and work related? How does heat affect resistance? How does heat affect pressure? In the morning, a concrete statue of specific heat = 600 j/(kg k) has a temperature of 15°c.... See all questions in Heat and Work Impact of this question 2155 views around the world You can reuse this answer Creative Commons License