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PH421/521: General Information

Last update: 1 November 2012

PH421/521: Oscillations is a 2-unit class within the Paradigms in Physics curriculum in the Physics Department at Oregon State University. Prerequisites are one year of introductory physics and 5 terms of 200-level mathematics. Some computing experience (PH265) is recommended but not required. Students are usually physics, computational physics, and engineering physics majors, but the course is accessible to and open to other science and engineering majors.

Course Description and Outcomes Times, Dates, and Locations Class email list; webpage Course Evaluation, Homework, Labs Participation Writing in PH421/521 Ground Rules, including collaboration Resources (texts, library, computer info) Add-Drop, Withdraw & Final dates Students with special needs


Course Description & Outcomes
PH421/521 is a course about oscillations, mostly simple harmonic oscillations, but also anharmonic oscillations. The course is focused around two experiments that investigate free and driven oscillations of damped mechanical and electrical systems. The main activity of the course is to prepare reports on these experiments, and homework assignments and worksheets are designed to assist you with this.

You will become familiar with two different simple oscillatory systems and learn to connect the mathematical descriptions with these physical examples. The rigid pendulum is a time-honored illustration of many important principles (and is capable of chaotic behavior when excited beyond the oscillatory regime studied here). The response function of an electrical circuit has its own importance as a widely used application of the central concept in linear circuit theory. Both systems are exploited to learn about the free and forced motion of damped and undamped oscillators. There is no example more important in physics!

The practical skills to be learned include mathematical techniques, problem-solving methodology, the foundation for a physicist's approach to the investigation of physical phenomena, and presentation techniques.
o Mathematical techniques include computing and inverting Fourier series and integrals, solving differential equations and applying initial conditions, and the use of complex exponentials and their connection to the physical quantities describing the systems.
o Problem-solving methodology includes learning to record, document, and analyze observations and calculations, and to investigate the realm of validity of simple models and approximations. These techniques will be exercised both in the laboratory and on the computer. Equally important are the skills of working with other scientists: oral and written communication, cooperating on complex activities, organizing a division of tasks when appropriate, gleaning knowledge from authoritative sources such as experts and books, and translating the notation and language to apply to the problem at hand.
o Presentation skills develop when data from experiments must be presented coherently and clearly, and linked to models of the physical system's behavior. Written presentation is emphasized in this course.

The central concept is the duality of time and frequency representations; the corresponding tool is the Fourier transform. In a mathematical introduction with stylized exercises, you will see examples of series of functions converging toward a limit. You will learn the concept and technique of Fourier transformation by predicting the time response of a simple electronic circuit from its measured frequency response, then comparing your prediction with observations.

The course will introduce computer-aided algebra and plotting using Mathematica, which is available from the computers in the classroom. You need no experience to begin with. Developing skill with Mathematica or similar programs like Maple or MathCad is important, and by the end of your physics degree, you must become be quite proficient in one of these.
o You will need basic facility with Microsoft Excel (or any spreadsheet program) to record, analyze and report experimental data.
o You will need basic facility with Microsoft Word (or any word-processing program), including generating equations, to report your laboratory experiment. Top of page

Times, Dates and Locations
  • Class meets MWF at 13:00 - 13:50 and TR at 12:00 - 13:50 from 11/5/2012 to 11/29/2012. There is no class on Thursday and Friday of Thanksgiving week; those classes are held on Monday and Tuesday of the following week.
  • Class meetings are in WGR 212.
  • Final exam: see below Add-Drop, Withdraw & Final dates.
  • This 2-credit course meets for 1/3 of the term. The work is thus concentrated and is equivalent to TWO 3-credit courses meeting 3 days/week for the full term.
  • Instructor & TA office hours are posted on the class web page.
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Class Web page, Email List
Course Evaluation
  • PH421: Homework 30%; Laboratory reports 40%; Final 30%.
    PH521: Homework 30%; Laboratory reports 40%; Final 30%.
    All lab reports and some class assignments will be submitted via blackboard (see syllabus page).
  • Grades are posted on Blackboard.
  • Homework: Assignments are posted on the class webpage. Homework is assigned on Mondays. A few problems are due on Wednesdays and the rest on Fridays. The intent is for you to work on the longer problems all week. Do not wait till Wednesday to begin the homework due on Friday. Most homework problems are directly related to the laboratory assignments. Required homework problems will be graded. Solutions will be posted immediately after class, on the due date. Assignments turned in after solutions are posted may not be eligible for full credit. Turn in partially completed assignments by the due date and the rest later for partial credit. Pay attention to your presentation - clarity, neatness, and logical structure contribute to the overall assessment. Make your solutions a model that a beginning sophomore in physics could work from. Please consult the writing guide.

    Practice problems provide examples for you to check whether or not you understand the material as we go along. They will not be graded. The "drills" posted on the web site are to help you to develop algebra skills using relevant mathematics. Most are not trivial; please complete them.

  • Laboratory reports:

    The first "report" is on the pendulum lab performed on the first Tuesday. This "report" is really a set of guided questions to help explain the expectations for data presentation. Much of the work will be done in class, so it is important to attend. In particular, the data analysis must be done on Tuesday night and brought to class the next day, where we will discuss your results and data presention. This intermediate assignment is worth 10% of the grade for that report. This report is due on the second Wednesday, via Blackboard.

    The second report is on the response of a series LRC circuit to a harmonic forcing function. Again,there is an intermediate data analysis due on the following day worth 10% of the grade. In class, we wil discuss results, physics, and reports. In the second report, you are expected to use the lessons from the first report to provide a clear, cohesive story about the lessons from this lab. It is due the third Wednesday, via Blackboard.

    Laboratory and computer exercises are performed in teams, but each student must be responsible for his or her own report. Please consult the writing guide and the rubrics. Please seek in-person, verbal feedback on your preliminary work from the instructor or the TA - we are here to guide you.

  • Final exam: The final exam involves problems similar to those encountered in the homework assignments, and the work explored in the physical and computational laboratory experiences. No programming will be required. You may write any equations or notes on one side of an 8.5"x11" sheet. Turn in this sheet with your exam.
  • PH521 requirements: Homework, laboratory portfolio, and writing in general are expected to reflect the more extensive scientific training & sophistication of a graduate student. The first laboratory assignment requires a more complete analysis of the anharmonic properties of the pendulum oscillation, and theoretical support of this analysis. The LRC circuit laboratory requires additional exploration of the circuit response to different driving forces. The homework assignments may have some different & higher-level problems.
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Class Participation
You must be actively engaged in learning in every mode of instruction. In lecture mode, listen actively (it's not trivial), and ask and respond to questions. In lab mode, question as you perform experiments. Observe carefully. You will often work together in groups in both lecture and lab mode. It is an efficient way to learn, because your peers are a vast source of information, largely untapped in traditional passive learning. It allows the instructor to address issues specific to smaller subsets of the class, while still having the entire class actively engaged. Learn to taken on all roles in a group - leader, questioner, scribe, reporter. You will find these skills are essential in a "real world" scientific environment. Learn actively, and be a good citizen in your group; do not abuse the system. Helping others learn elevates the level of your own learning. But do not rely on others to get you through. It is ALWAYS your responsibility to go over group work alone to ensure that YOU have have understood the information discussed. Top of page
Writing in PH421
Writing is a critical aspect of your professional development. Its importance cannot be overstressed. The writing guide page is intended to help you improve and evaluate your homework assignments and laboratory reports. Top of page
Ground Rules
Science is inherently a social and collaborative effort, each scientist building on the work of others. Nevertheless, each student must ultimately be responsible for his or her own education. Therefore, you are expected to abide by a number of Ground Rules:
  • We strongly encourage students to work with each other, more advanced students, the TA, and the professor. However, each student is expected to turn in independent assignments that show evidence of individual thought. The final synthesis must be entirely your own. This applies also to, and especially to, computer-generated worksheets. NEVER work together so closely with someone that you produce the same solution or Mathematica worksheet. This invariably means that one person has been the dominant partner and it is impossible for the instructor to determine who it was. Such assignments will be returned ungraded, and both (or all) students requested to turn in a new assignment different from each other and different from the original.
  • Homework solutions from previous years are very strictly off-limits. You are on your honor not to use them, and not to share your homework solutions with other students. Allow faculty to use their time interacting with you, rather than continually thinking up new assignments. Besides, if you don't do the work yourself, it will show up very clearly on exams later. Likewise, the solutions provided by the instructors are for your personal use only. You may make one copy and keep it in your personal files.
  • Sources must be appropriately documented. If you work with other students in a laboratory assignment, you must write down who your partners were. If you find part of a homework problem worked out somewhere (other than homework solutions from previous years), you may use that resource; just make sure you reference it properly. If someone else helps you solve a problem, reference that too. In a research paper, the appropriate reference would be
    Jane Doe, (private communication).
  • Plagiarism - representing someone else's work as your own - is unethical, but collaboration and exchange of ideas is healthy. You can avoid collaborative efforts taking on the look of plagiarism by acknowledging sources and by writing up your work independently.
Some students find it difficult to decide what constitutes too much collaboration. Here are some guidelines:
  • Under no circumstances may you ever copy another student's work, even if you have collaborated to work through the problem. Under no circumstances may you ever allow your own work to be copied. Violation of this rule will certainly result in a zero grade for the assignment, and may result in an F grade in the course.
  • Try to make progress on a problem on your own. If you cannot, seek help from other resources to overcome a specific hurdle, then try to make further headway on your own. Once you have solved the problem, be honest with yourself about how much intellectual input came from you, and try to improve next time. Rewrite the problem solution without reference to any notes, explaining the steps as you go, as you would to a novice problem solver. Once you have done this, you will have generated a unique solution and one that will have taught you something about what you really understand. Do not be discouraged if you find that some problems require hints and help all the way through.
  • A good test of your understanding is to explain a problem to someone else. Be conscious of your role in a collaboration. If it is clear that you have mastered the problem and your collaborator is a novice, limit your help to put the person on the track to solving the problem alone. Do not give too much help. Conversely, if you are seeking help from an expert, don't allow the expert to guide you all the way through. If the exchange is between people of a similar level of understanding, keep challenging one another, asking questions and providing answers, going beyond the limits of the problem. This is the fun part of physics - endless discussion about interesting problems! (There is no intention to categorize students as "weak" or "strong". Expert and novice can refer to two students of equal talent and ability - but one happens to have already solved the problem!)
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Resources
The main Paradigms webpage lists all the Paradigms texts, and gives information about the OSU library.
Texts: For PH421, you will find useful
  • (T) Taylor, Classical Mechanics (required, used often)
  • (M) Main, Vibrations and Waves in Physics, 3rd Edition (required, used often)
  • (RHB) Riley, Hobson & Bence, 2nd ed, Mathematical Methods for Physics & Engineering, (mostly reference, alternatives acceptable)
  • (K) Knight, Physics for scientists and engineers, 2nd edition (or whichever text you used for your calculus-based introductory Physics course.
  • (GEM) Griffiths, Introduction to Electrodynamics, 3rd Edition (used for some examples, also text for PH320, PH422)
  • (TM) Thornton & Marion, Classical Dynamics of Particles and Systems, 5th Edition (was used prior to Taylor)
  • The following two books are electronics texts, and such books are useful for alternative discussion of the LRC circuit.
  • (S) Simpson, Introductory Electronics for Scientists and Engineers, 2nd Edition (PH411 text, not required, helpful for LRC circuit)
  • (B) D. V. Bugg, Electronics: Circuits, Amplifiers and Gates, (Institute of Physics Publishing, Bristol, 1991). Recommended supplement. (Used for PH 411 in previous years. Horowitz and Hill; Simpson have similar information).
Computers: Please see the Paradigms Homepage about computer requirements for the course.
  • The class makes use of Mathematica, a computer algebra program. You don't need any experience; familiarity with any programming environment is all that is needed, along with a willingness to learn. The Mathematica page provides more resources.
  • Prior knowledge of Excel or similar spreadsheet program will be useful. It is not required, but expect to learn a great deal.
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Add, Drop, Withdraw & Final Exam Dates
  • Special add/drop dates are in effect for the Paradigms courses. Please see the Paradigms Web page for the dates.
  • Final exams also have special days. PH421 in Fall 2012 is the third Paradigm of the term, so the final is during finals week on the regularly scheduled date for a Mon 13:00 class. Please see the university exam schedule. The exam will be held in WGR 304 & 304F, and other rooms as needed.
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Students with Special Needs
Students with documented disabilities who may need accommodation, who have any medical information which the instructor should know of, or who need special arrangements in the event of evacuation, should make an appointment to discuss their needs with the instructor as early as possible, and no later than the first 3 days of the class. Top of page