1. Electric Potential Energy
Example problems from the textbook

2. Exercise 12, p. 592
It takes +6.0 J of work to move two charges from a large distance apart to 1.0cm from one another. If the charges have the same magnitude,
How large is each charge?
ANSWER: 2.6 µC
(b) What can you tell about their signs?
ANSWER: same sign

3. Exercise 10, p. 592
How much work is required to completely separate two charges (each -1.4 µC) and leave them at rest if they were initially 8.0mm apart? Is the work required positive or negative? Electric field does the work. ANSWER: -2.2 J

4. Exercise 15, p. 592
Compute the energy necessary to bring together (from a very large distance) the charges in the configuration show in the figure: ANSWER: –0.72 J

5. Exercise 14, p. 592
An electron is moved from point A to point B and then to point C along two legs of an equilateral triangle with sides of length 0.25m. If the horizontal electric field is 15 N/C, what is the magnitude of the work required? ANSWER: –6.0 x 10-19J