Electric Forces and Electric Fields

Student Learning Objectives
Lessons / Lecture Notes
Important Equations
Example Problems
Pencasts
Applets and Animations
Videos

Student Learning Objectives

• To become familiar with basic electric phenomena.
• To learn the charge model and apply it to conductors and insulators.
• To understand polarization and the attraction between neutral and charged objects.
• To understand and use Coulomb’s law for point charges.
• To recognize and use the principle of superposition for electric forces.
• To understand the field model and the concept of a field.
• To learn the electric field of the point charge.
• To use the principle of superposition to calculate the electric field of multiple point charges.

Lessons / Lecture Notes

The Physics Classroom (conceptual)

PY106 Notes from Boston University (algebra-based):

Introductory physics notes from University of Winnipeg (algebra-based):

HyperPhysics (calculus-based)

PHY2049 notes from Florida Atlantic University (calculus-based):

PHY2044 notes from Florida Atlantic University (calculus-based)

General Physics II notes from ETSU (calculus-based)

Important Equations

Example Problems

Problem 1
Three point charges are fixed in place in a right triangle. What is the electric force on the –0.60-µC charge due to the other two charges? (Solutions)

Problem 2
(a) A tiny ball (mass = 0.012 kg) carries a charge of –18 µC. What electric field (magnitude and direction) is needed to cause the ball to float above the ground? (Solutions)

(b) Two charges are placed on the x axis. One charge (q1 = +8.5 µC) is at x1 = +3.0 cm and the other (q2 = -21 µC) is at x2 = +9.0 cm. Find the net electric field (magnitude and direction) at x = +6.0 cm. (Solutions)

Pencasts

Electric Forces
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