Answer
$r=1.39 m$
Work Step by Step
According to coulomb's law
$F=\frac{q_1q_2}{4\pi{\epsilon_{\circ}}r^2}$
or
$r=\sqrt{\frac{q_1q_2}{4\pi{\epsilon_{\circ}}F}}$
putting the values, we get
$r=\sqrt{\frac{26\times10^{-6}\times47\times10^{-6}}{4(3.14)(8.854\times10^{-12})(5.70)}}$
$r=1.39 m$
