The situation can be shown as
From energy conservation,
$( PE )_{\text {initial }}+( KE )_{\text {initial }}=( PE )_{\text {final }}+( KE )_{\text {final }}$
$0+0=\frac{K e^{2}}{r}+\frac{1}{2} m v^{2}+\frac{1}{2} m v^{2}$
$\Rightarrow v=\sqrt{\frac{K e^{2}}{m r}}=\sqrt{\frac{9 \times 10^{9} \times\left(1.6 \times 10^{-19}\right)^{2}}{1.67 \times 10^{27} \times 10 \times 10^{-2}}}$
$=1.17 \,ms ^{-1}$


