Question

14. In reference to the two previous questions, let 7. = 800°C and stions, let T = 800°C and T = 50°C. What is the c- Carnot efficiency of this engine? IS. A coal-fired electrical gencrating plant operates at an efficiency of 38%. The temperature of the steam leaving the boiler is 550°C and the temperature of the environment is 20°C. What percentage of the maximum ideal (Carnot) efficiency does that plant attain? _ Show your work: 16. Write down a statement of the Second Law of Thermodynamics. 17. Which of the following situations would be allowed by the Second Law of Thermodynamics? a) converting 100 joules of heat energy into 100 joules of work b) the passage of heat from an iceberg into the surrounding ocean water that is at a temperature of 10°C c) the reduction of waste heat from a power plant to zero with new technology d) none of the above. 18. If the R-value of a wall is 10 f2-F-hr/Blu, then the rate of heat transfer through a 2fx31 section of wall, with AT = 50°F will be a) 10 Btu/hr b) 30 Btu/br c ) 500 Btu/h d) 3000 Btu/hr 19. For a given kind of material (of fixed thermal conductivity), the R-value increases if the piece of the material is made a) thicker b) thinner c) of greater surface area d) none of these

Answer 1

0-14 THE Souc= 1073K Tc: 50'c : 323K Efficiency of cannot cycle (y) = 1 - 1 Ти EI - 323 : 1-0.301 ? 0.69 0-15 marximum Ideau cannot efficiency Icarnot 1 - 2737 20 273+550 ? 0.640 = 64°), Now, the queshon is what percentate 7 64 is 38. let it be a i, 249 647 = 387. a ax6913 387 Q R = 38 x 100 = 59.37% Q-16 I am writing tho claunus Stelternenti- It is impossible to construct a device as heat pump that operates in a cycle and produces no effect other that transter of heat from lower temperature to higher temperature bocly.

hotter O nome of the above a) All neut can't be converted into work b) Heat can't flow from colder body to on its owen. c) waste heat can never be reduced to zeno. As per Chegy guidelines, I have solved your queshons, Please upuote if the answer was helpful.