12.2 First law of Thermodynamics: Thermal Energy and Work
12.4 Applications of Thermodynamics: Heat Engines, Heat Pumps, and Refrigerators
A coal power station functions at 40.0 percent efficiency. What is the amount of work it does if it takes in 1.20×1012 J by heat?
- 3×1010 J
- 4.8×1011 J
- 3×1012 J
- 4.8×1013 J
A heat engine functions with 70.7 percent thermal efficiency and consumes 12.0 kJ from heat daily. If its efficiency were raised to 75.0 percent, how much energy from heat would be saved daily, while providing the same output?
- −10.8 kJ
- −1.08 kJ
- 0.7 kJ
- 7 kJ