F = Kq1q2r2\frac{Kq_1q_2}{r^2}r2Kq1q2
F = 9×109×(1.0×10−6)2(0.2)2\frac{9 \times 10^9 \times (1.0 \times 10^{-6})^2}{(0.2)^2}(0.2)29×109×(1.0×10−6)2
= 2.25 x 10−1^{-1}−1N
