$$
\begin{aligned}
q_{1} &=+2 \mu C =2 \times 10^{-6} C \\
q_{2} &=+2 \mu C =2 \times 10^{-6} C \\
r &=50 cm \\
&=\left(\frac{50}{100}\right) m =0.5 m
\end{aligned}
$$
se use coulomb's law of electrostatics
$$
\begin{aligned} &=\frac{k q_{1} q_{2}}{r^{2}}=\frac{9 \times 10^{9} \times\left(2 \times 10^{-6}\right)^{2}}{(0.5)^{2}} \\
&=0.144 N
\end{aligned}
$$