P H Y M O D E R N P H Y S I C S. Introduction

Transcription

1 P H Y M O D E R N P H Y S I C S SPRING 2010 INSTRUCTOR: Dr. Tracy M. Hodge OFFICE: Science 112 PHONE x3301 tracy_hodge@berea.edu OFFICE HOURS: MWF 2:00-3:00 WF 10:00-11:00 Th 1:30-3:00 Text: Modern Physics, 2 nd ed., Randy Harris, Pearson-Addison Wesley (2008) Course Website: Introduction The goal of the course is to familiarize the student with the principles of modern physics, enable the student to apply those principles quantitatively in all areas of natural science, and to develop an appreciation for the major discoveries that revolutionized physics in the 20 th Century. Students will use inquiry-based and quantitative methods to investigate the foundations of modern physics including waveparticle duality, quantum mechanics, atomic and nuclear, physics, and the theory of relativity. At the end of the course students should be able to: 1. Discuss Einstein s two postulates of relativity and demonstrate how the postulates lead to time dilation and length contraction; 2. Solve quantitative problems using the Lorentz transformations; distinguish between time-like and space-like events; calculate velocity transformations and solve problems involving relativistic momentum and energy; 3. Discuss the Principle of Equivalence and the General Theory of Relativity. 4. Solve diffraction and interference problems for sound waves, light waves, and particles; 5. Describe the experimental evidence leading to quantum theory including the Compton effect, Bragg scattering, the photoelectric effect, and blackbody radiation; 6. Discuss de Broglie s formalism of matter waves and its relationship to probability density; calculate the de Broglie wavelength for a variety of particles; apply

2 debroglie s results to derive the Bohr model of the atom; understand the origin and meaning of the uncertainty principle; 7. Find stationary state solutions to the Schrödinger equation for one-dimensional systems including the particle in the box, the finite well, the harmonic oscillator, and simple step potentials; 8. Derive the general form of Schrödinger s equation for the hydrogen atom, including separation of variables; know the four quantum numbers and their physical significance; understand spin and orbital angular momentum; 9. Explain the size, stability, and other properties of nuclei based upon quantum mechanical results; know the radioactive decay law, modes of radioactivity, and applications of radioactive decay. Course Requirements As a general rule, you should expect to put in 2 hours of work outside of class for each credit hour. That means for a 3-hour lecture/lab course you should spend at least 6 hours outside of the classroom every week. You will spend that time reading the text, taking notes, completing homework assignments, writing lab reports, and studying for quizzes and exams. The requirements of the course include: Reading the Text Reading the text should familiarize you with the central ideas of each chapter, and I will not spend class time reviewing basic formulas or definitions. Rather, you should consider the lecture as an opportunity to discuss the more difficult concepts, apply problem-solving techniques, and examine certain topics in more depth. Feel free to ask questions about specific points that you don t understand. You are responsible for reading the text before you come to class. As you read the text, jot down a few notes and questions to help you remember the basic principles of the chapter. Re-read sections that are particularly confusing. Try the exercises scattered through the chapter. It is often a good idea to re-read the text after class, to help you absorb the material. Homework Problem solving is essential to a real understanding of physics, and will be the major focus of this course. Homework assignments will include a wide variety of quantitative problems. Problem sets will be due at the beginning of class on Monday. Homework sets will count towards 30% of your grade in the course. Late homework will not, as a rule, be accepted. Lab Lab is mandatory and will meet once a week for a period of two hours. Over the course of the semester you will be required to complete several experiments that illustrate the fundamental principles of modern physics. You will be expected to keep thorough, wellorganized lab notebook documenting your work in the lab. Your lab notebook will count towards 10% of your total grade.

3 Research Presentation You are required to write an original, word typed essay on a recently awarded Nobel Prize in physics ( ). Describe the work and its importance to science recognized by the award. As part of your research you will be expected to read at least one original, peer-reviewed article by the prize winner, and attach a copy of the article to your essay. Material from the Web can only be used as supplemental material (include the link). Your essay topic and a one paragraph summary are due in class on Monday, March 1 st. The final draft of your essay is due two weeks later on March 15. Be sure and plan your time accordingly. A good place to start is the Nobel Museum at nobelprize.org. Physics Today also has good review articles each time the prize is awarded. Exams There will be three hour-term exams and a comprehensive final exam. Two of the three exams will count towards 12% of your grade; your lowest exam score will count 6%; and the final exam will count 20%. Attendance Attendance during lecture and laboratory is mandatory. You are allowed up to four free absences during the semester, after which each absence will decrease your final grade by 2%. Course Grade Your final course grade will depend on the following elements: Homework 30% Presentation 10% Lab Notebook 10% Three exams ( ) 30% Final exam 20% Grades will be based on a standard scale: A 92-99%; A %; B %; B 82-87% B 80-82%; C %; C 72-77%; C %; D 61-68%; F <61%.

4 Academic Honesty (from the student handbook) Students are expected to be scrupulous in their observance of high standards of honesty in regard to tests, assignments, term papers, and all other procedures relating to class work. Academic dishonesty as used here includes, but is not limited to, plagiarism, cheating on examinations, theft of examinations or other materials from an instructor's files or office or from a room in which these are being copied, copying of an instructor's test material without the permission of the instructor, theft of computer files from another person, or attributing to one's self the work of others, with or without the others' permission. Suspected cases of academic dishonesty will result in loss of credit for the assignment and will be referred to the Associate Provost for Advising and Academic Success. Student Special Needs Services: If anyone in this class is in need of special academic accommodations and is already registered with the Special Needs Services Office, please make an appointment with the instructor to discuss such accommodations. Upon request, this syllabus can be made available in alternative forms. If you need academic accommodations and are not already registered with the Special Needs Services Office, please contact Bev Penkalski in Room 4 of Fairchild Hall (ground floor) or by telephone at (859)

5 Tentative Course Schedule Week 1 Week 2 Topic Ch 2: Special Relativity Time dilation, length contraction Lorentz equations Velocity equations & the Doppler effect Ch 2: Special Relativity Relativistic energy and momentum General relativity Homework 17,24,34,36,43,57,59,64 69,75,76,78,84,94,97, ,111 Week 3 Interference and Diffraction TBA EXAM I Week 4 Ch 3: Waves and Particles I 11,15,17,23,31,45,47,49, Blackbody radiation 52,53 The photoelectric effect The Compton effect & pair production Week 5 Ch 4: Waves and Particles II 11,13,16,17,21,37,44,52, The de Broglie wavelength 71,72 Probability densit and the wave function The Uncertainty Principle Week 6 Ch 4: Waves and Particles II The Bohr model of the atom 22,25,28,34,47,78-88 Ch 5: Bound States The infinite well The finite well Week 7 The quantum harmonic oscillator Expectation values 49,53,57,59-62,66,69 EXAM II Week 8 Ch 6: Unbound States The potential step 13,17,21,22,36 Tunneling and alpha decay Group and phase velocity Week 9-10 Ch 7: The Hydrogen Atom Separation of variables and the 3d SE A: 18,20,32,37,40,42 Quantization of angular momentum B: 43,45,49,54,55,89 Solution of the radial equation Week 11 Ch 8: Spin and Atomic Physics Spin and the Pauli exclusion principle 27,30,31,34,41,48,49 The periodic table and spectroscopic notation 62,65,71,74,75 Spin-orbit coupling EXAM III Week TBD

6 L A B P O L I C Y You will be expected to keep a clear and well-organized record of your lab work in a dedicated lab notebook. Your lab notebook will be collected for grading no later than two class days after you conduct the experiment: notebooks will be collected on Friday for the Wednesay afternoon lab, and on Monday for the Thursday morning lab. Tentative Lab Schedule: The first lab exercise is designed to increase your awareness and understanding of measurement uncertainty. Each week thereafter you will conduct one experiment from modern physics. Lab instructions will be available on the moodle site for the course. 1. Introduction to Measurement (2 weeks) 2. Inteference and Diffraction 3. Blackbody Radiation 4. The Charge/Mass Ratio of the Electron 5. The Photoelectric Effect 6. Spectroscopy of the Hydrogen Atom 7. The Franck-Herz Experiment 8. The Particle in a Box 9. Nuclear Decay The Lab Notebook 1 A lab notebook is intended to be a true and permanent record of your work. It may seem tedious or even unnecessary to you, but it is an important part of any lab experience. The notebook should be complete enough that you could refer back to it in a few years and repeat the experiments. General Guidelines: The Notebook must be permanently bound: no loose-leaf or spiral notebooks. Handwriting must be legible. Your TA will not grade materials that he or she cannot easily read. All notes should be taken in pen with the exception of colored drawings that may be done with pencils. Errors should be crossed through with a single line, not erased or obliterated. All information in the notebook must be handwritten or represent actual results, such 1 Adapted from the Molecular, Cellular and Developmental Biology (MCDB) department at the University of Colorado, Boulder.

7 as photographs or printouts. Everything you do in the laboratory should be recorded in your lab notebooks, including notes, drawings, data, speculations, etc. Everything from your initial strategy through planning, execution and interpretation and should be in your notebook. Keep all of your lab-related notes, including lab lecture notes, in one notebook. Keep a separate binder for the lab manual and lab handouts. Keep in mind that reports and presentations will be prepared from the notebook. You should have much more information recorded in your notebook than you can or should put on a poster or into a presentation. The notebook should include: The first two pages reserved for a table of contents. Notes from lab lectures, discussions and your own research. Answers to assigned questions. Prelab Section for experiments: Title of experiment and date. The Objective(s) of the lab: what you are trying to do and why you are trying to do it. The Procedure in flow chart or outline form. This should not be an exact copy of the lab manual instructions, but reworked in a manner easy for you to follow. Any deviations from your written procedure. This includes changes both intentional and accidental. Observations: everything that happens during your experiment that may have a bearing on the outcome or interpretation of the experiment (this includes color, precipitate, time, temperature, etc). Data: raw and calculated. Use complete sentences, tables and graphs where appropriate. Show sample calculations with steps and units. Discussion: Interpret your results. Refer back to your predictions. Draw conclusions about experiment. Make suggestions for further experiments or refinements to the procedure.