15.3 Introduction to the Second Law of Thermodynamics: Heat Engines and Their Efficiency

A certain heat engine does 10.0 kJ of work and 8.50 kJ of heat transfer occurs to the environment in a cyclical process. (a) What was the heat transfer into this engine? (b) What was the engine’s efficiency?

(a) What is the work output of a cyclical heat engine having a 22.0% efficiency and $6 . \text{00} \times \text{10}^{9} \text{ J}$ of heat transfer into the engine? (b) How much heat transfer occurs to the environment?

The engine of a large ship does $2 . \text{00} \times \text{10}^{8} \text{ J}$ of work with an efficiency of 5.00%. (a) How much heat transfer occurs to the environment? (b) How many barrels of fuel are consumed, if each barrel produces $6 . \text{00} \times \text{10}^{9} \text{ J}$ of heat transfer when burned?

Assume that the turbines at a coal-powered power plant were upgraded, resulting in an improvement in efficiency of 3.32%. Assume that prior to the upgrade the power station had an efficiency of 36% and that the heat transfer into the engine in one day is still the same at $2 . \text{50} \times \text{10}^{\text{14}} \text{ J}$. (a) How much more electrical energy is produced due to the upgrade? (b) How much less heat transfer occurs to the environmen…