Physics 305

Electricity and Magnetism

Class:	TR 9:45 a.m. - 11:00 a.m., D-208
Professor:	G.P.Gilfoyle; Office: Gottwald Science Center, D-104; phone: 289-8255; electronic mail: ggilfoyl@richmond.edu; Office Hours: MW 2:30-4:30 pm, TR 3:30-4:30 am. Other times by appointment or availability.
Objective:	To gain an understanding of the fundamentals of electrical and magnetic phenomena.
Textbook:	Introduction to Electrodynamics by David J. Griffiths, 3rd edition (required), Mathematical Handbook of Formulas and Tables by Murray Spiegel (Schaum's Outline Series) (recommended), Mathematical Methods in the Physical Sciences, M.L.Boas, 3rd edition (recommended; You better have it anyway!) or Mathematics for the Physical Sciences, J.B.Seaborn (recommended).
Prerequisites:	Physics 301 or permission of the department.
Course Work:	Each class meeting will consist of some combination of lecture, demonstration, or student presentation (see SCHEDULE).
Attendance:	Attendance at all classes is expected. An excused absence is one given by the dean, a doctor, or a department. An excusable absence is one that the instructor excuses for what he deems to be sufficient reason. Only the dean can excuse an absence from a test or exam. A student is responsible for all work missed during an absence.
Grading:	Grades will be computed on the following basis:

Homework	40%
Tests	30% (15% for each of 2 tests)
Final Exam	30%

Make-up tests and laboratories will not be administered. If a test is missed because of an excused absence the next test will count more heavily to make up the loss. Unexcused absences will result in a grade of zero for the missed activity.

Homework:

Homework will be assigned regularly, but only a fraction of it will be collected or presented to the class. The exams will be based on these assignments and it is utter madness to neglect them. Late homework will be accepted, but unexcused, late, submissions will be reduced by one point if not handed in at the start of class, another point if not handed in by the end of that day, and one point for each day late thereafter. Late submissions will be excused only at the discretion of the instructor.

Homework:

Like all physics courses one the best ways to understand the material is to work through the assigned problem sets. I will ask you to turn in formal solutions to some problems or make presentations to the class and will grade each problem using a 0-10 scale. Others will appear on the exams. In writing up solutions, you should follow the basic outline of problem solving below. Emphasize the proper use of notation, mathematical precision, and discuss the physical principles being brought to bear on the solution. I encourage you to work collaboratively on the problems but you should understand that when you write up solutions the work is to be your own (i.e., don't just copy someone's solution). You should properly reference sources you use outside the texts discussed above. Feel free to see me for help with the homework. Check the website for the latest information on the class assignments at the following address. http://facultystaff.richmond.edu/~ggilfoyl/em.html

Exams:

Tests and exams will consist of short-answer questions and problems. The final exam will be comprehensive. See the Schedule for dates and times.

Problem Solving Framework
by F. Reif

1. Analyze the Problem: Bring the problem into a form facilitating its subsequent solution.
   • Basic Description - clearly specify the problem by
     • describing the situation, summarizing by drawing diagram(s) accompanied by some words, and by introducing useful symbols; and
     • specifying compactly the goal(s) of the problem (wanted unknowns, symbolically or numerically.)
   • Refined Description - analyze the problem further by
     • specifying the time sequence of events (e.g., by visualizing the motion of the objects as they might be observed in successive movie frames, and identifying the time intervals where the description of the situation is distinctly different (e.g., where acceleration of the object is different); and
     • describing the situation in terms of important physics concepts (e.g., by specifying information about velocity, acceleration, forces, etc.).

2. Construct a Solution: Solve simpler sub-problems repeatedly until the original problem has been solved:
   • Choose sub-problems by
     • examining the status of the problem at any stage by identifying the available known and unknown information, and the obstacles hindering a solution;
     • identifying available options for sub-problems that can help overcome the obstacles; and
     • selecting a useful sub-problem among these options.
   • If the obstacle is lack of useful information, then apply a basic relation (from general physics knowledge, such as $m\vec a = \vec F_{TOT}$ , $F_k = \mu N$, $x = (1/2)a_xt^2$) to some object or system at some time (or between some times) along some direction. Eliminate the unwanted quantity by combining two (or more) relations containing this quantity.
   Note: Keep track of wanted unknowns (underlined twice) and unwanted unknowns (underlined once).

3. Check and Revise: A solution is rarely free of errors and should be regarded as provisional until checked and appropriately revised.
   • Goals attained? Has all wanted information been found?
   • Well-specified? Are answers expressed in terms of known quantities? Are units specified? Are both magnitudes and directions of vectors specified?
   • Self-consistent? Are units in equations consistent? Are signs (or directions) on both sides of an equation consistent?
   • Consistent with other known information? Are values sensible (e.g., consistent with known magnitudes)? Are answers consistent with special cases (e.g., with extreme or especially simple cases)? Are answers consistent with known dependence (e.g., with knowledge of how quantities increase or decrease)?
   • Optimal? Are answers and solutions as clear and simple as possible? Is answer a general algebraic expression rather than a mere number?

Gilfoyle's rules of thumb for writing up homework solutions

1. Read the problem carefully.

2. Draw a picture with all the relevant quantities.

3. Write down the knowns.

4. Write down the unknowns.

5. State the necessary starting points (i.e. equations).

6. Cite sources when appropriate. For example, we've all know Coulomb's Law since our earliest childhood, but we may not remember the results from problem 2-5.

7. Do/Explain the math. Use proper notation at all times. Clearly define any near variable or quantities you introduce. Clearly delineate subproblems (I use nested, wiggly lines).

8. Clearly state the final results.

9. Layout of problem should flow logically.

10. When in doubt, consult your text or your notes (maybe). This way of doing things should become natural as you metamorphosize into a real physicist.

Physics 305 Schedule

Spring 2009

Date		Topic (Chapter)		Date		Topic (Chapter)
Jan	13	Electrostatics (2)		Mar	10	Spring Break
	15	"			12	"
	20	"			17	Magnetostatics (5)
	22	"			19	"
	27	More Electrostatics (3)			24	Test 2
	29	"			26	Magnetic Fields in Matter (6)
Feb	3	"			31	"
	5	"		Apr	2	"
	10	Test 1			7	"
	12	Electric Fields in Matter (4)			9	Electrodynamics (7)
	17	"			14	"
	19	"			16	"
	24	"			21	"
	26	"			23	"
Mar	3	Magnetostatics (5)
	5	"

Final Exam: Tuesday, April 28, 9-12 noon.