(a) (b) Conceptual E-Field Strength 4. This question is similar to questions given on previous exams. Every student should feel comfortable solving it. Each situation (a)-(f) in the figure to the right shows two locations ,1 and 2, near two point charges. For each case, compare the electric field strengths the two charges create at the locations. Check the appropriate box for (c) (d) 2. each case. (e) (0 Situation %3D (a) (b) (c) (d) (e) (f)

Three balls, with charges of +4g, -2q, and -q, are equally spaced along a line. The spacing between neighboring balls is r. We can arrange the balls in three different ways, as shown in the figure. In each case, the balls are in an isolated region of space very far from anything else. Treat the balls as point charges. +4g -29 -2g 2 || 1 +4q -g +4q (a) Rank the arrangements according to their potential energy, from most positive to most negative. See if you can do this without explicitly calculating the potential energy in each case. (Use only ">" or "=" symbols. Do not include any parentheses around the letters or symbols.) (b) Using q = 3.40 x 10-6 C and r = 35.0 cm, calculate the electrostatic potential energy in each of the cases above. 1: 2: 3:

Charge q, = 2.50 nC is at x, = 0 and charge q, = 6.00 nC is at x, = 4.00 m. At what point between the two charges is the electric field equal to zero? (Enter the x coordinate in m.) HINT Write an expression for the net electric field as a function of position, x, in the region between the two charges. (Don't forget that the electric field is a vector, so direction is important!) Set this expression equal to zero and solve for the variable x using the quadratic equation. Click the hint button again to remove this hint. m

Could some one please explain the best way to solve this problem and show all work