Solution to task 306 from Chertov´s for extramural stud

Solution to task 306 from Chertov´s for extramural stud

306. Point charges Q1 = 30 µC and Q2 = -20 µC are at a distance d = 20 cm from each other. Determine the strength of the electric field E at a point remote from the first charge at a distance r1 = 30 cm, a from the second - at r2 = 15 cm.