1. Consider point a which is 70 cm north of a -4.2 µC point charge, and point b which is 74 cm west of the charge (Fig. 17-23). (a) Determine Vba = Vb - Va. (b) Determine Eb - Ea. Magnitude Direction (counterclockwise from east is positive) 2. Vb-Va=(EPEb/q)-(EPEa/q) 3. I thought I would use that formula since that is what I need, but I don't know how to get V. Please help!