COLORADO STATE UNIVERSITY
DEPARTMENT OF PHYSICS
Spring Semester 2008
Ph142 - Physics for Scientists and Engineers
PROBLEM SET 6 - CHAPTER 25 - ELECTRIC CURRENT AND DC CIRCUITS
DUE AT THE START OF RECITATION CLASS ON 06 MARCH 2008
Some guidelines for problem solving (whether handed in and graded or not):
Focus is on understanding and implementation, not “plug and chug” problems.
Almost every problem will involve some
level of conceptual understanding and some challenge in the mathematical set-up and parameterization.
Do your work on grid style engineering paper.
Use one side of the page only.
Start each problem on a new page and state the problem number clearly.
Put your name, section number, problem set number, and due date on every page.
Include proper and reasonably professional looking diagrams or sketches for each problem.
(6) Assemble in problem order (#1, #2, #3, etc.) and staple your pages in the upper left corner.
For assigned problems, your work (here and on future problem sets) should be accompanied by:
A clear problem statement in words, diagrams, and equations (not a regurgitation of the problem text in Tipler and
Mosca, necessarily, but adequate for some one to know what the problem is without going back to the book).
Good clear well labeled diagrams.
Well developed equations with all parameters defined.
Graphs with clearly defined and labeled axes, etc.
You should parameterize all problems.
That is, assign algebraic parameters to all relevant variables and constants,
set the problem up algebraically, and solve algebraically.
Only then (if numerical evaluations are required), should you
begin to plug in numbers.
When you do plug in numbers, if it is a simple exercise, do as much of the evaluation as you can
by hand (not by calculator).
Multiply and cancel simple factors, add and subtract powers of ten, etc., to obtain a simplified
numerical expression for evaluation.
Often, you will find that you do not even need to do a calculator evaluation!
If it is a
complicated evaluation, you may wish to use some appropriate software, such as MathCad, etc.
A Problem Set will generally have from five to ten problems.
If your recitation instructor decides to grade
problems in some fashion, he or she may give partial credit, when deserved.
However, there will be no credit for nonsense.
Everything you say must make sense.
Take care to do some intelligent work on ALL the problems.
One completely missing
problem can have a serious effect on your understanding and (if graded) on your Problem Set grade.