[tex]Dane:\\q_1 = 2 \ mC =2\cdot10^{-3} \ C\\q_2 = 3 \ mC = 3\cdot10^{-3} \ C\\r = 10 \ cm = 0,1 \ m = 10^{-1} \ m\\k = 9\cdot10^{9}\frac{Nm^{2}}{C^{2}}\\Szukane:\\F_{c} = ?\\\\\\F_{c} = k\cdot\frac{q_1\cdot q_2}{r^{2}}\\\\F_{c} = 9\cdot10^{9}\frac{Nm^{2}}{C^{2}}\cdot\frac{2\cdot10^{-3} \ C \cdot3\cdot10^{-3} \ C}{(10^{-1} \ m)^{2}}[/tex]
[tex]F_{c} = 54\cdot10^{5} \ N\\\\\boxed{F_{c} = 5,4\cdot10^{6} \ N = 5,4 \ MN}[/tex]
