Download Phys 2426 Principles of Physics II

Phys 2426 Principles of Physics II Instructor David Hobbs Office: AG 108 Office Hours: MW 8:30am‐11:00am, F 9:00am‐12:00pm Phone: (806)894‐9611, ext. 2639 email: [email protected] Course Description Content Phys 2426 is the second semester of a two‐semester calculus‐based introduction to physics. The course serves to provide the student with the physics background necessary for continued study in engineering and the physical sciences. This course covers electricity and magnetism emphasizing the concepts of electric and magnetic fields and extending the study of the atomic structure of matter to include the role of electrons. Prerequisites Completion of PHYS 2425 ‐ Principles of Physics I is required before taking Phys 2426. Course Overview This course deals with electric and magnetic interactions, which are central to the structure of matter, to chemical and biological phenomena, and to the design and operation of most modern technology. The main goal of the course is to have you engage in a process central to science: the attempt to model a broad range of physical phenomena using a small set of powerful fundamental principles. The specific focus of the course is an introduction to field theory, in terms of the classical theory of electricity and magnetism. The course also emphasizes the atomic structure of matter, especially the role of electrons and protons in matter. Topics include: •
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electric field matter and electric fields, polarization of atomic matter electric field of distributed charges, setting up physical integrals, numerical integration electric potential magnetic field, atomic model of ferromagnetism a microscopic view of electric circuits, surface‐charge model capacitors, resistors, and batteries, macroscopic view of electric circuits magnetic force, including motional emf patterns of field in space (Gauss’s law and Ampere’s law) Faraday’s law, with emphasis on curly electric field electromagnetic radiation, including production by accelerated charges and re‐radiation due to charges accelerated by radiative electric fields (classical interaction of light and matter) electromagnetic waves and physical optics geometric optics Approach The course will emphasize rigorous problem‐solving in physics using a student‐centered active learning environment. Class sessions will require students to be responsive, to think, and to perform hands‐on tasks. Key concepts of new material will be discussed in short lectures. Lab time will be interspersed with classroom discussion. If you devote a sufficient amount of time each day to studying physics, you will be in a position to attack physics problems efficiently, based on a clear understanding of the fundamental physical principles that underlie all successful analyses. Collaborative Work Scientists and engineers work in groups as well as alone. Social interactions are critical to their success. Most good ideas grow out of discussions with colleagues. This course encourages collaborative teamwork, a skill that is valued by most employers. As you study together, help your partners to get over confusions, ask each other questions, and critique each others’ homework write‐ups. Teach each other! You can learn a great deal by teaching. But remember that you are responsible for understanding all details of a problem solution. You must turn in your own clearly organized solution. While collaboration is the rule in technical work, evaluations of individuals also play an important role in science and engineering. Quizzes and exams are to be done without help from others. Study requirements In addition to your time in class each week, you are expected to spend about 10 hours studying outside of class. If you typically spend less than 8 hours in outside study, you are unlikely to be able to learn the material. If you typically spend more than 12 hours in outside study, it is extremely important that you consult with me about ways to study more efficiently. It is important to keep up with the class. New concepts introduced in this course build on earlier ones, so mastering key concepts is critical. If you get behind, seek help right away! Attendance policy Attendance and effort are vital to success in this course. Class attendance keeps you well connected to the course, so that you know at all times what’s going on, what are the most important points, etc., and gives you opportunities to ask questions and clear up confusions. Therefore, students are expected to be in attendance for every class session. To emphasize the importance of class attendance, a small percentage of your final course grade will be based on attendance. Absences due to illness or a college‐sponsored activity will be excused provided you furnish appropriate documentation (A note from the school nurse or a doctor, official college documentation for college‐sponsored activities). Unexcused absences will result in a grade of zero for the attendance portion of your final course grade. After four unexcused absences, you will be dropped from the class with an “F”. If you stop attending class and wish to avoid an “F” you must obtain an official drop form, have it signed, and take the completed form to the registrar’s office before your fourth absence. See the current class schedule for the last day you can drop a class. Textbook The textbook is Matter & Interactions, 3rd edition by R. Chabay and B. Sherwood (John Wiley & Sons, 2011). There is no lab manual for this course. WebAssign Homework assignments will be delivered and graded on WebAssign, a computer homework system. WebAssign access codes come packaged with a new textbook if purchased from the SPC bookstore. You can also purchase access codes online at www.webassign.net. Assignments Readings A key component of the course is the textbook, in which you are asked to analyze phenomena, to work out small examples, to make some of the steps in derivations, etc. Class discussion will not cover all of the assigned material; it is essential that you study the textbook carefully. Class sessions will be devoted to discussion of ideas (rather than to introducing them), clarifying points of confusion, and activities of various kinds that allow you to practice using the concepts you have read about in the text. The text thus provides the background for these activities. Therefore, it is essential to read the appropriate sections in the textbook BEFORE coming to class. The basic knowledge for the course is contained in the textbook and the number one expectation of you is that you will read carefully and thoroughly to find and learn that knowledge. Your time in class will be largely ineffective if you have not studied the appropriate text sections prior to coming to class. You are expected to do the “stop and think” questions (marked in the text by ) as you encounter them during your reading of the text. You should also work the in‐line exercises as QUESTION
you come to them during your reading; you will turn in some of these through the WebAssign homework system. Be sure to note any of these that you cannot figure out and seek help on them. It is important that you take this study assignment seriously, a day at a time. If you ignore the book until it is time to attack an assigned homework problem, you are likely to waste a lot of time floundering around, desperately searching for a nonexistent magic formula somewhere in the chapter that sort of matches the homework problem, and you will lose the opportunity to acquire a deep understanding of the material. If on the other hand you devote a modest amount of daily time to working through assigned sections of the book, you will be in a position to attack the homework problems efficiently, based on a clear understanding of the fundamental physical principles that underlie the analysis of all the homework problems. You will also be prepared for exams, which test your understanding of the fundamental principles rather than your ability to plug numbers into secondary special‐case formulas. Homework A WebAssign homework assignment will be due at 12:00 pm every Monday, Wednesday, and Friday. These assignments will consist of some inline exercises from the textbook and a small number of problems from the end of the textbook chapter. You are allowed a limited number of submissions. You should work each assignment on separate papers (different from the WebAssign page) showing how you solved the problem. This will help you when reviewing the assignments before a test. Important: It will usually take you much longer to complete the WebAssign work if you do not first read the textbook sections and do the exercises in the textbook, because you won’t be properly prepared and will find yourself floundering around, trying one answer after another. Computer work You will be assigned computer homework, some of which will be done in class, and some to be done outside of class. I will teach you the techniques you will need; no previous programming experience is assumed. The computer activities emphasize computer modeling of physical systems and are designed to deepen your understanding of the nature of the modeling process. Computer modeling is an important technique that is playing an increasingly critical role in all of engineering and science. Computer programming is a powerful tool, but even the most skilled programmer sometimes gets waylaid by a computer problem that is very difficult to “debug.” For that reason we will use the following rule: If you have worked seriously for an hour trying without success to debug a malfunctioning computer program, STOP! Get help from me or from another student before continuing. I do not want you to spend hours and hours struggling with computer problems. I can make adjustments of deadlines if necessary. However, you have the responsibility to start on an assignment early enough to be able to get help if necessary. Don’t wait until 2 AM of the day the assignment is due! Getting help with assignments You should ask lots of questions in class to clear up any initial confusion you might have about a topic. I also encourage you to avail yourself of my help during office hours. I keep my office door closed since my office is located across from the restrooms and the hallway tends to see a lot of noisy traffic, but you are always welcome to come get help. If you fall behind for any reason, please let me know as soon as possible. The sooner I know about these situations, the better I can help you make up work. I will do what I can to help you complete the course satisfactorily. Laboratory During lab you will typically work in groups of three students on the following three kinds of activities: •
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Experiments, involving measurement and analysis of data according to fundamental principles. Computer modeling, involving constructing 3‐D models of electric and magnetic fields and their effects on charged objects. This will involve the VPython programming language. No previous programming experience is needed – I will teach you the basic concepts needed. Group problem solving, involving work on large, complex problems. In lab you may begin work on a large problem to be completed outside class or the entire problem may be solved during class. You must attend class during the day the lab is done in order to receive credit. If you have an excused absence, you will be excused from the lab you missed, and your lab average will be taken from your remaining labs. If you miss a lab, you should work with your classmates to be sure you understand the missed lab activities since these will be covered on tests. Tests Quizzes Several short unannounced quizzes will be given during the semester. You will be given 10 minutes to answer one or two short questions. These quiz questions will be very similar to the inline exercises in your textbook, so the best way to prepare is to keep up with the reading assignments and be sure you understand all the inline exercises. If you miss a quiz due to an excused absence, you will be excused from the quiz, and your quiz average will be taken from your remaining quizzes. Tests Tests will be given during regular class sessions as indicated on the course calendar. All tests will be closed‐book, but some relevant formulas and constants will be provided. You will receive a list of objectives and review suggestions along with the formulas to be provided about one week prior to each test. If you have an excused absence, you will need to contact the instructor to make up the test. Final exam A comprehensive final exam will cover all of the course material. It will be given during the scheduled final exam time as shown in the schedule of classes and on the course calendar. If the final exam grade is higher than the lowest test grade, it will be counted twice and the lowest test grade will be dropped. Grade calculation Your final grade will be assigned based on your overall, weighted class average using the weighting scheme shown below: Weighting Scheme Task Code Weight Attendance A 3% Homework HW 15% Lab LAB 15% Quizzes Q 7% Tests (3) T 45% Final Exam E 15% The letter grades will be based on a fixed scale as follows: A: 90 – 100 B: 80 – 89 C: 70 – 79 D: 60 – 69 F: below 60 If everyone in the class does well, grades are not curved downward. Everyone can get an A. There usually is a "gray area" between two letter grades for borderline cases (grades within 0.5 points of the break point). Earning the higher grade in these cases depends on your interactions in class and whether your test and homework performance shows improvement during the course of the semester. Miscellaneous information In this class, the teacher will establish and support an environment that values and nurtures individual and group differences and encourages engagement and interaction. Understanding and respecting multiple experiences and perspectives will serve to challenge and stimulate all of us to learn about others, about the larger world and about ourselves. By promoting diversity and intellectual exchange, we will not only mirror society as it is, but also model society as it should and can be. Students with disabilities, including but not limited to physical, psychiatric, or learning disabilities, who wish to request accommodations in this class should notify the Special Services Office early in the semester so that the appropriate arrangements may be made. In accordance with federal law, a student requesting accommodations must provide acceptable documentation of his/her disability to the Special Services Coordinator. For more information, call or visit the Special Services Office in the Student Services building on the Levelland campus, 894‐9611 ext. 2529 or call or visit the Special Services Office in rooms 809 and 811, Reese Center Building 8, 885‐3048 ext. 4654. Course Objectives Measurable learning objectives students should achieve after one year of introductory physics are listed below. 1.
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Students should develop a good functional understanding of physics. They should be able to: a. describe and explain physics concepts including knowing where and when they apply. b. apply physics concepts when solving problems and examining physical phenomena. c. apply concepts in new contexts (transfer). d. translate between multiple‐representations of the same concept (for example: between words, equations, graphs, and diagrams). e. combine concepts when analyzing a situation. f. evaluate explanations of physical phenomena. Students should begin developing expert‐like problem solving skills. They should be able to: a. apply a small set of fundamental physical principles to a wide variety of physical situations. b. use these principles to satisfactorily solve standard textbook problems. c. model complicated physical systems by making approximations and idealizations in order to be able to apply fundamental principles. d. solve more challenging problems, including: context‐rich ("Real World") problems, estimation problems, multi‐step problems, multi‐concept problems, problems requiring qualitative reasoning. e. evaluate other people’s written solutions and solution plans. 3. Students should develop laboratory skills. They should be able to: a. interact (set up, calibrate, set zero, determine uncertainty, etc.) with an apparatus and make measurements. b. explain the physical principles underlying the operation of the apparatus, measurements, physical situation being studied and analysis of data. c. design, execute, analyze, and explain a scientific experiment to test a hypothesis. d. evaluate someone else’s experimental design. 4. Students should develop technology skills. They should be able to: a. create simple computer models of physical situations. b. utilize a spreadsheet to graph and do curve fitting. c. find information on the web. d. use microcomputer, video, and web‐based software and hardware for data collection and analysis. 5. Students should improve their communication, interpersonal, and questioning skills. They should be able to: a. express understanding in written and oral forms by explaining their reasoning to peers. b. demonstrate their knowledge and understanding of physics in written assignments. c. discuss experimental observations and findings. d. present a well‐reasoned argument supported by observations and physical evidence. e. evaluate oral arguments, both their own and those espoused by others. f. function well in a group. g. evaluate the functioning of their group. 6. Students should retain and/or develop student cognitive attitudes and beliefs (expectations) that are favorable for learning physics with deep understanding. They should: a. believe that understanding physics means understanding the underlying concepts and principles instead of focusing on knowing and using equations. b. see physics as a coherent framework of ideas that can be used to understand many different physical situations. c. see what they are learning in the classroom as useful and strongly connected to the real world. d. be cognizant of the scientific process/approach and how to apply it. e. indicate a willingness to continue learning about physics and its applications. f. see themselves as part of a classroom community of learners. Calendar Phys 2426.001 Week 1 2 3 4 5 6 7 8 9 10 Spring 2011 Monday Lecture Monday Lab
01/17 MLK Day – No Class 01/24 Sections 14.4 – 14.8 Electric Field of a point charge; Superposition principle; Electric field of a dipole; retardation VPython Review/Intro
01/31 Section 15.6 – 15.7; 16.2 Model of a metal; Charging and discharging; field of a charged rod 02/07 Sections 16.6 – 17.3 Capacitor; Field of a sphere; Potential energy; Systems of charged objects; Potential difference in a uniform field Experiment: Determining the amount of charge on an ordinary object 02/14 Sections 17.7 – 18.2 Potential at one location; potential difference in insulators; Energy density; Electron current; Detecting magnetic fields 02/21 Sections 18.3 – 18.7 Biot‐Savart law for a moving charge; Electron current and conventional current; Biot‐
Savart law for currents; magnetic field of a straight wire 02/28 Sections 18.11, 19.1 – 19.3 Atomic structure of magnets; current in parts of a circuit; Electric field and current Review for Test 1
03/07 Sections 19.8 – 19.10 Energy conservation in circuits; Applications (solving circuit problems); Detecting surface charge 03/21 Sections 20.3 – 20.6 Work and power in a circuit; Batteries; Meters; RC circuits 03/28 Sections 21.1 – 21.3 Magnetic force on a moving charge; Magnetic force on a wire; electric and magnetic forces; velocity selector Whiteboard problems
Wednesday Lecture
01/19
Vector Appendix Section 14.1 – 14.3 3D Vectors, Electric Field 01/26
Sections 15.1 – 15.6 Charged particles in matter; charging an insulator; Polarization; Interaction of charged and neutral matter; conductors and insulators; model of a metal 02/02
Sections 16.3 – 16.5 Procedure for calculating field of distributed charge; field of a ring; disk 02/09
Sections 17.4 – 17.6 Sign of potential difference; Potential difference in a nonuniform field; Path independence and round trip potential difference 02/16
Test 1 Chapters 14 – 16 Wednesday Lab
Review of Group Roles
VPython: Electric field of a point charge VPython: Electric field of a dipole VPython: Electric field of a charged rod, part I Experiment: Measuring potential differences 02/23
Sections 18.8 – 18.10 Magnetic field of a circular loop of current; magnetic dipole moment; Magnetic field of a bar magnet VPython: Electric field of a charged rod, part II Experiment: Magnetic field of a long straight wire 03/02
Sections 19.4 – 19.7 Surface charge on wires in circuits; The initial transient; Feedback; Surface charge and resistors 03/09
Sections 20.1 – 20.2 Capacitors in circuits; Charging and discharging capacitors; Capacitance; Resistors and Ohm’s law 03/23
Test 2 Chapters 17 – 19 VPython: Magnetic field of a moving point charge 03/30
Sections 21.4 – 21.5 The Hall effect; motional emf Experiment: Capacitors
Whiteboard problems
Review for Test 2
Experiment: Energy in circuits Experiment: Magnetic Dipoles Calendar 11 12 13 14 15 16 04/04 Sections 21.5 – 21.9 More on motional emf; Magnetic force in a moving reference frame; magnetic torque; Magnetic potential energy; Motors and generators 04/11 Sections 22.4 – 22.6 Reasoning from Gauss’s law; Gauss’s law for magnetism; Ampere’s law Experiment: Macroscopic circuit analysis 04/06
Sections 22.1 – 22.3 Patterns of electric fields; electric flux; Gauss’s law VPython: Magnetic force on a moving charged particle Experiment: Building a simple motor Experiment: Faraday’s Law
04/18 Sections 23.2 – 23.4, 23.6 Applying Faraday’s law; Faraday’s law and motional emf; inductance Whiteboard problems
04/25 Easter – No Class 04/13
Sections 22.7, 23.1 – 23.2 Maxwell’s equations; Changing magnetic fields and curly electric fields; Faraday’s law 04/20
Sections 24.1 – 24.4 Maxwell’s equations; fields traveling through space; accelerated charges produce radiation; sinusoidal radiation 04/27
Test 3 Chapters 20 – 23 05/02 Sections 24.5 – 24.6 Energy and momentum in radiation; Effect of radiation on matter; polarization of radiation 05/09 Review for Final Exam
05/04
Sections 24.7 – 24.10 Light propagation through a medium; refraction and Snell’s law; Lenses; Image formation 05/11
Final Exam 10:15am – 12:15pm Review for Test 3
Experiment: Optics