1. Phys 150 Lecture 31 Please sit together in pairs: –Onyema and Honglu –Alejandra and Matt –Chris and Lin –Ryan and Anwen –John F. and Mengyue –Walter and Melissa –Max and Zhongyun –Amanda and Kaijun –Pauline and Erich –Jake and Irfan –John W. and Jason –Jennifer and Jiayuan –Alexandra and Erica –David and Dian –Abigael and Michael

2. Phys 150 Lecture 42 Announcements Homework 3 is due on Sunday at midnight. Quiz on Chapter 3 on Tuesday.

3. Phys 150 Lecture 53 Chapter 2 – Atoms and Heat Steam engine Stirling engine Liquid N 2 engine Car engine

4. Phys 150 Lecture 54 Stirling engine

5. Phys 150 Lecture 55 Steam engine

6. Phys 150 Lecture 56 i>clicker question A coal-fired power plant to produce electricity has an efficiency of typically A.33% B.50% C.75% D.90%

7. Phys 150 Lecture 57 i>clicker question A coal-fired power plant to produce electricity has an efficiency of typically A.33% - modern plants can achieve 48% B.50% C.75% D.90% Can also burn natural gas instead of coal Maximum efficiency = (T hot – T cold )/ T hot

8. Phys 150 Lecture 58 Steam turbine

9. Phys 150 Lecture 59 Gas turbine

10. Phys 150 Lecture 510 i>clicker question A modern gas turbine can achieve an efficiency of A.45% B.60% C.75% D.90%

11. Phys 150 Lecture 511 i>clicker question A modern gas turbine can achieve an efficiency of A.45% B.60% C.75% D.90%

12. Phys 150 Lecture 512 Wind turbine

13. Phys 150 Lecture 513

14. Phys 150 Lecture 514 i>clicker question Which fuel is the most energy efficient for an automobile? A.Diesel fuel B.High octane gasoline C.Low octane gasoline D.E85

15. Phys 150 Lecture 515 i>clicker question Which fuel is the most energy efficient for an automobile? A.Diesel fuel – 30% B.High octane gasoline – 20% + C.Low octane gasoline – 20% - D.E85 A.Diesel fuel burns hottest B.High octane burns hotter than low octane (please use the octane specified for your engine) Maximum efficiency = (T hot – T cold )/ T hot

16. Phys 150 Lecture 516 Thermal Expansion Things expand when heated, contract when cooled. Different materials expand at different rates. Metal rod

17. Phys 150 Lecture 517 Thermal Expansion Thermometer

18. Phys 150 Lecture 518 i>clicker question If the Earth’s temperature were to rise by about 4 C, the sea level would rise by about A.3 mm B.6 cm C.0.5 m D.7 m

19. Phys 150 Lecture 519 i>clicker question If the Earth’s temperature were to rise by about 4 C, the sea level would rise by about A.3 mm B.6 cm C.0.5 m D.7 m

20. Phys 150 Lecture 520 IPCC 2007 2/3 expansion, 1/3 melting ice

21. Phys 150 Lecture 521 Thermal Expansion If temperature rises by 2.4 – 6.4 C in 2100 –Sea level rise of 0.26 – 0.59 m –About half of this is due to expansion, half due to melting ice. –Ignores possible rapid melting of Greenland –Melting of Greenland inevitable if temperature rises 3 C: 7 m of sea level rise! Thermometer