Physics 2213
Homework #1
Spring 2010
Read:
Chapter 21:
intro., sections 21.1-4, 21.5 (thru p. 729), 21.7
(Can you do Ex. 21.15 on p. 738 by the common denominator method?)
Basic Ideas:
Electric Charge & Conservation of Electric Charge
Electric Force & Coulomb's Law
Vector Fields & the Electric Field
Superposition Principle
Math Skills:
Geometry, Trigonometry, Symmetry Principles
Vector Analysis (especially addition by geometry & components)
Asymptotic and limiting power law forms for functions
Learning Goals:
(Be sure you understand where and how each goal applies to homework, discussion,
lecture, and lab activities.)
*
Determine the magnitude, direction, and components of the net electric force on any
specified point charge due to a collection of other point charges by applying Coulomb's Law
and the Superposition Principle to electric force vectors.
*
Explain how a neutral object can become electrically polarized by a nearby charged object,
how a neutral object can experience a net electric force due to a charged object, and how a
neutral object produce an electric force on a charged object.
*
Distinguish between electric force and electric field, and explain how they are related.
*
Determine and sketch electric field vectors obtained by vector constructions using the
Superposition Principle for these charge distributions:
point charge (+ or -), electric dipole
(+ - pair), 2 like charges (both + or -).
*
Conceptually translate an equation for electric field as a function of position into a graph
(without doing detailed numerical calculations).
*
Determine the asymptotic limiting forms of the electric field as a function of position at small
and large distances from a set of electric charges, and tell what these forms mean physically.
*
Show that algebraic and numerical results have correct units and are physically reasonable.
For extra practice:
Chap. 21:
Q's #Q21.1-7, 11-22
(not turned in or quizzed)
E's & P's: #21.7, 11, 21, 25, 27, 49, 73, 81
To be prepared for a Quiz on Wednesday-Friday, Feb. 3-5, at your 2nd weekly Discussion
*** FOR EACH HW ASSIGNMENT:
Be sure to organize your work
neatly
so that
YOU
have
a clear idea of what the problem and solution entail.
Include carefully drawn and labeled
diagrams to assist you and illustrate your reasoning.
Be sure you understand thoroughly
what you did and can identify each basic principle you used and tell why you used it.
Be
sure you can repeat and explain your solutions and reasoning
without
referring to your HW
paper or other reference materials.
Be sure you can provide arguments to check and support
the physical and mathematical validity and correctness of your solutions. ***
#Q21.10