\(f_{32}=k\ \frac{Q_3\ Q_2}{r_{32}}=\left(9x10^9\ \frac{nm^2}{c^2}\right)\left(\frac{\left(65x10^{-6}c\right)\left(50x10^{-6}c\right)}{\left(0.03m\right)^2}\right)=325n\)
\(f_{31}=k\ \frac{Q_3\ Q_1}{r_{31}}=\left(9x10^9\ \frac{nm^2}{c^2}\right)\left(\frac{\left(-86x10^{-6}c\right)\left(86x10^{-6}c\right)}{\left(0,06m\right)^2}\right)=139.75n\)