The three charges shown in Figure 20-33 are held in place as a fourth charge, q, is brought from infinity to the point P. The charge q starts at rest at infinity and is also at rest when it is placed at the point P.

Figure 20-33,

(a) If q is a positive charge, is the work required to bring it to the point P positive, negative, or zero? Explain.
(b) Find the value of q if the work needed to bring it to point P is -1.3 × 10-11 J?

Transcribed Image Text:

+7.45 µC 1.25 m 1.25 m, P! 1.25 m +2.75 µC -1.72 µC