PHY 113 C General Physics I 11 AM – 12:15 P M MWF Olin 101 Plan for Lecture 25:

1. PHY 113 C General Physics I • 11 AM – 12:15 PM MWF Olin 101 • Plan for Lecture 25: • Comments on Exam 3 • Pep talk on preparing for Final Exam • Comprehensive review – Part I • Bonus attendance points for Lecture 26 • – Part II of comprehensive review & course assessment PHY 113 C Fall 2013 -- Lecture 25

2. PHY 113 C Fall 2013 -- Lecture 25

3. Final exam schedule for PHY 113 C PHY 113 C Fall 2013 -- Lecture 25

4. Comments on Final Exam • It will be comprehensive (covering material from Chapters 1-22) • It is scheduled for 9 AM Dec. 12th in Olin 101 • In class format, but there will be no time pressure • May bring equation sheets according to your vote PHY 113 C Fall 2013 -- Lecture 25

5. Comments on Exam 3 • iclicker question • Which of the following statements matches your recollections of the exam: • It was too hard • It was too easy • The Thanksgiving holiday erased all recollections of the exam Solutions are now posted: http://users.wfu.edu/natalie/f13phy113/solutions/ PHY 113 C Fall 2013 -- Lecture 25

6. Two versions of take-home portion of exam PHY 113 C Fall 2013 -- Lecture 25

7. Take home portion of Exam 3 -- continued PHY 113 C Fall 2013 -- Lecture 25

8. Take home portion of Exam 3 -- continued PHY 113 C Fall 2013 -- Lecture 25

9. Take home portion of Exam 3 – continued • Two problems with question: • Round-off error in adiabatic step • Error in Lecture 21 notes (now corrected) PHY 113 C Fall 2013 -- Lecture 25

10. Corrected equations from #21: Work done on a system which is an ideal gas: “Adiabatic” (no heat flow in the process process) For ideal gas: PVg = PiVig Qi®f= 0 Pi P (1.013 x 105) Pa Vi Vf PHY 113 C Fall 2013 -- Lecture 25

11. Further comments on adiabatic processes PHY 113 C Fall 2013 -- Lecture 25

12. Take home portion of Exam 3 -- continued PHY 113 C Fall 2013 -- Lecture 25

13. iclicker question • This problem • Of all the problems that might appear on the final exam, this one would be the worst. • Of all the problems that might appear on the final exam, this one would not be the worst. • This example has inspired me to look into designing better engines or heat pumps. PHY 113 C Fall 2013 -- Lecture 25

14. In-class portion of Exam 3 PHY 113 C Fall 2013 -- Lecture 25

15. In-class portion of Exam 3 -- continued toward away PHY 113 C Fall 2013 -- Lecture 25

16. In-class portion of Exam 3 -- continued VS VS f’=480 Hz f’=560 Hz PHY 113 C Fall 2013 -- Lecture 25

17. f’=480 Hz f’=560 Hz VS VS PHY 113 C Fall 2013 -- Lecture 25

18. In-class portion of Exam 3 -- continued PHY 113 C Fall 2013 -- Lecture 25

19. In-class portion of Exam 3 -- continued FB mg PHY 113 C Fall 2013 -- Lecture 25

20. In-class portion of Exam 3 -- continued • iclicker question • This density seems correct. • This density seems wrong. PHY 113 C Fall 2013 -- Lecture 25

21. In-class portion of Exam 3 -- continued PHY 113 C Fall 2013 -- Lecture 25

22. In-class portion of Exam 3 -- continued PHY 113 C Fall 2013 -- Lecture 25

23. Back to the discussion of the Final exam: • iclickerquestion • What is the purpose of the Final Exam? • Pure pain and suffering • Assessment of student learning • Gateway to medical school or other professional career • Help students to “solidify” knowledge of physics and further develop problem solving skills • All of the these PHY 113 C Fall 2013 -- Lecture 25

24. iclicker question • How many equation sheets should you prepare for Final Exam? • 0 • 1 • 2 • 3 • 4 PHY 113 C Fall 2013 -- Lecture 25

25. General advice on how to prepare for Final Exam • Review fundamental concepts and their corresponding equations • Develop equation sheet(s) that helps you solve example problems on all of the material. You can assume that empirical constants and parameters will be given to you; they need not take up space on your equation sheet. • Practice problem solving techniques. • If you discover unanswered questions, please contact me. PHY 113 C Fall 2013 -- Lecture 25

26. Problem solving skills Equation Sheet Math skills • Advice: • Keep basic concepts and equations at the top of your head. • Practice problem solving and math skills • Develop an equation sheet that you can consult. PHY 113 C Fall 2013 -- Lecture 25 26

27. Problem solving steps • Visualize problem – labeling variables • Determine which basic physical principle(s) apply • Write down the appropriate equations using the variables defined in step 1. • Check whether you have the correct amount of information to solve the problem (same number of knowns and unknowns). • Solve the equations. • Check whether your answer makes sense (units, order of magnitude, etc.). PHY 113 C Fall 2013 -- Lecture 25

28. Specific review material -- standing sound waves General wave equation: wave propagation distance time wave speed PHY 113 C Fall 2013 -- Lecture 25

29. Specific review material -- standing sound waves Periodic wave: phase (radians) Periodic traveling waves: velocity (m/s) period (s); T = 1/f wave length (m) Amplitude PHY 113 C Fall 2013 -- Lecture 25

30. Combinations of waves (“superposition”) “Standing” wave: PHY 113 C Fall 2013 -- Lecture 25

31. Specific review material -- standing sound waves open-open open-closed y(x,t) is density fluctuations in the air v=vsound» 343 m/s PHY 113 C Fall 2013 -- Lecture 25

32. Specific review material -- standing string waves (which can couple to sound) L PHY 113 C Fall 2013 -- Lecture 25

33. iclicker question • How can we hear a standing wave on a string? • The string couples to the air to produce a sound wave at the same wavelength • The string couples to the air to produce a sound wave at the same frequency • You cannot hear a standing wave on a string PHY 113 C Fall 2013 -- Lecture 25

34. Bonus attendance points for Lecture 26 • – Part II of comprehensive review & course assessment • Bonus points for emailing in questions you would like to discuss in Lecture 26 PHY 113 C Fall 2013 -- Lecture 25