Physics 228 Thermal Physics, Optics, and Relativity Fall 2008 Lecture Location: Room 220, Chem-Phys Bldg

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Physics 228 Thermal Physics, Optics, and Relativity Fall 2008 Lecture Location: Room 220, Chem-Phys Bldg. Lecture Time: MWF 12:00 noon -12:50 pm Lecturer: Prof. Ganpathy Murthy Recitation Times: To be determined Office: Room 295B, Chem-Phys Bldg. Office Hours: To be determined Telephone: 257-4729 E-mail: [email protected] Grader: Gen Wang Grader email: [email protected] Grader office/phone: CP 250, 257-3941

Success in this course will require your committment, diligence, and persistence. A good rule of thumb to keep in mind is that you should be putting in about 5-6 hours of work outside class for every hour of formal instruction. Since there are 3 hours of formal instruction per week in this course, you should be spending at least 15-20 hours per week outside class on this course reading the notes/text, solving the practice problems, coming to oﬃce hours for help, etc.

Course Description Goals: To think analytically, and retain, organize and employ facts purposefully, critically and eﬀec- tively. To strive to harness this way of thinking to help you understand, assess, appreciate and criticize modern science and technology. Phy 228 is the third semester of our introductory physics sequence for students who will use some physics in their future careers. In Phy 228, you will study Thermal Physics, Optics, and Special Relativity. These are some of the most challenging and sometimes counterintuitive phenomena in physics, and mastery of the course material will prepare you for more advanced topics such as Quantum Mechanics and General Relativity. Please read this entire syllabus carefully, and refer to it often. If you have any question about the structure or administration of the course, you are likely to ﬁnd the answer here.

Textbook not required I am going to be sending you detailed notes in pdf form every week, so there is no need to buy a special textbook for this course. If you do want to refer to a book, much of the material will be in any standard textbook on calculus-based physics, such as Physics for Scientists and Engineers by Serway and Jewett. An excellent reference book for the part of the course dealiing with Special Relativity is Spacetime Physics by Taylor and Wheeler. In any case, always read the notes before you come to class, so that you are prepared with questions. Occasionally, I will have a “ﬂipped” class, where we work problems during class. In such cases, it is absolutely essential that you read and understand the material before you come to class.

Class Meetings Phy 228 meets formally for three hours per week. You should expect to spend at least ﬁve hours studying physics outside of class for each hour you spend inside. The lecture class will meet three hours per week (MWF 12:00 noon – 12:50 pm) in the lecture/demonstration hall CP 220. The lectures will

1 roughly follow the notes that I send you. I will assume that you have read the assignment before coming to class. Unless explicitly mentioned in class, students are responsible for both material assigned as reading (even if we do not “cover it” in class) and material presented in lecture. These lectures will be devoted to examining your current conceptions, demonstrating physical phenomena, describing quantitatively the characteristics of physical phenomena, and establishing relationships among them. These relationships are most easily expressed in mathematical terms. While the mathematical prerequisite for this course is MA114 (differential and integral calculus of one variable), bear in mind that a prerequisite represents the minimum that you have to know when you enter the class. You will definitely be learning new mathematics during this course. During the first class, we will arrange a mutually convenient time to meet as a group to gain practice in solving problems. I have often heard students say that they understand the concepts but feel unsure in approaching problems. Solving problems is the surest way to deepen your understanding of the material, and to achieve mastery over it. Our emphasis will be on an understanding of the underlying physics concepts as well as on problem- solving skills. In addition to being able to solve all of the assigned problems, you will also be expected to be able to apply the concepts involved in these problems to somewhat different situations. This may involve qualitative and sometimes creative answers to questions or problems. It will thus be good practice for the exams if you attempt to do additional problems, either of your own devising, or from some textbook.

Examinations and Grading Your course grade will be determined as follows: In-class exams (2 x 100) 200 Final exam 200 Homework grade 200

Total 600

An overall score of 541 or higher (out of 600) will fetch a grade of A: Between 481 and 540 a grade of B: Between 421 and 480 a grade of C: Between 361 and 420 a grade of D. Any overall score 360 or below will be worth a grade of E. Please note that there is no “curve”, and it is your performance alone that will determine your grade. Exams: There will be two in-class midterm exams and a two-hour final exam, roughly a third of which will be devoted to the material covered after the last exam, the other two-thirds comprehensive. The midterms will be on February 3 and March 12 during class. The final exam will be at 10:30am on May 7th, in class. Any student who cheats on any exam will receive a grade of E for the course, and may be subject to further disciplinary action by the university. Communication between students is absolutely forbidden during quizzes and exams. If you have a question, you should ask the instructor, who will be present. If you miss a exam without a valid excuse, you will receive a zero for the exam. If you have a valid excuse (e.g. signed note from a physician or a university official), present it to me. An excused absence always requires a written request. It must be provided to the me at least one week in advance except for unexpected emergencies in the immediate family or for the student. If you miss a single exam with an excused absence, you will be given either a make-up exam (which will not be less demanding than the exam missed), or a calculated replacement grade to restore the points lost on the missed exam. In the latter case, your grade for the missing exam will be calculated from your ranking on the other fifty-minute exam. If you miss the final examination or a fifty-minute exam, you may,

2 upon request, get an I-grade only if you have a valid excuse and the average of your exam scores indicates a possibility of passing the course. You will have to complete the course at another time. If you wish to submit a exam for re-grading, first make sure that you understand how to do the problem correctly (see the posted solutions, for example). Then, within a couple of days of receiving your exam back, provide an explanation of your request on a separate signed sheet of paper, and hand it to me. Make no marks on the solution that you submit for re-grading, so that it can be compared with the photocopy on file. (Exams will be photocopied before they are returned.) Any appeals concerning grades for exams must be resolved within two weeks of receiving your exam back. At semester’s end, do not appeal for a reconsideration of a score assigned weeks previously. Homework grade: Homework will be given every Monday and will be due the next Monday. They will be graded and returned by that Friday. As I mentioned before, solving problems is an integral part of learning the material, and is worth one-third of the total course grade. After the homework is due I will post detailed solutions. I strongly encourage you to come to me before the homework is due to make sure that you are on the right track. While I encourage you to discuss physics (including the problem sets in this course) with your classmates, please make sure that you understand the solution completely and write it yourself in your own words. Interactivity: lectures if you attempt to become actively engaged. Ask yourself questions about what you have read and make predictions about the outcomes of real or imagined experiments. One of the most important things to do is ask me questions in class if you don’t understand what I am saying: I will take as long as necessary to make the concept clear before moving on. While you may feel hesitant to expose your ignorance, chances are that someone else has the same question and he/she will be grateful to you. Sometimes in lecture, we will go over several “concept questions”; the purpose is to focus our attention on important concepts. We will discuss these questions first individually, then in informal groups formed in class, and then as a whole class. However, no formal grade will be associated with this activity. As mentioned previously, we will arrange a mutually convenient time to meet and discuss the problems as a group. While this will not be reflected in your credit hours, it is strongly recommended that you attend these meetings.

Course Evaluations Course evaluations are an important (and mandatory!) component of our Department’s instructional program. An on-line course evaluation system is in place to allow each student ample time to evaluate each component of the course and instructor, thus providing the Department with meaningful numerical scores and detailed commentary while minimizing the loss of instructional time in the classroom. The evaluation system is open from April 14 through April 30. To access the system during this time, simply go the Department of Physics Web page at pa.as.uky.edu and click on the link for Course Evaluations; then follow the instructions. You will need to use your student ID number to log into the system, and this will also allow us to monitor who has ﬁlled out evaluations. However, when you log-in you will be assigned a random number that will keep all your comments and scores anonymous.

Miscellaneous Information

All the lecture notes, problem sets, solutions, etc, will be posted on my personal webpage http://www.pa.uky.edu/˜murthy/courses/phy228s14 You can navigate to this page from the “oﬃcial” PHY228 course website http://pa.as.uky.edu/courses/2014/Spring/PHY/228/001

3 If you have a documented disability you can request an accomodation through the Disability Resources Center http://www.uky.edu/StudentAﬀairs/DisabilityResourceCenter/current.html Please review the student code (see http://www.uky.edu/StudentAﬀairs/Code/index.html) of rights and responsibilities, especially with regard to academic integrity (good), cheating and plagiarism (bad), and decorum and civility in the classroom (good).

List of topics Phy 228 is divided into three roughly equal parts.

• Thermal and Statistical Physics

– Temperature and Heat. The mechanical equivalent of heat and the conservation of energy. Ideal gases and the absolute zero of temperature. – The first and second laws of Thermodynamics. The Carnot cycle and the Carnot-Clausius definition of the entropy as a state function. – The Ergodic hypothesis, counting of microstates, and the microscopic definition of the entropy. The entropy of 2D and 3D Ideal gases. Temperature and pressure as derivatives of the entropy. – Systems in contact with reservoirs. The Gibbs distribution. Helmholz and Gibbs free energies. Phase transitions. – Boltzmann’s Kinetic Theory of gases. The H-Theorem and the statistical nature of the Second Law. The Arrow of Time: From Microscopic Reversibility and Macroscopic Irreversibility.

• Geometric and Wave Optics

– Review of reflection and refraction, Snell’s Law. Lenses and mirrors. Fermat’s principle of least time. – Maxwell’s equations. Light as transverse Electromagnetic waves. Interference and Diffraction. – Radiation from a hot object, blackbody radiation. The Ultraviolet Catastrophe and Planck’s solution. – The quantum-mechanical particle nature of light. The Photoelectric effect.

• Einstein’s Special Theory of Relativity

– The Principle of Relativity. Galilean Relativity as applied to Newtonian Mechanics. – The incompatibility between Maxwell’s equations and Galilean Relativity. Something’s gotta give! – The Postulate of Relativity: The speed of light is independent of the motion of the observer. – Lorentz transformations, length contraction, time dilation, and the twin paradox. – Four-vectors, relativistic kinematics and collisions.