Two identical particles, each with a mass of 10 g and a charge of...

Initial potential energy of the system is given by $U_i = \dfrac{1}{4\pi\epsilon_0} \dfrac{q^2}{r}$

Substituting the given values:

$U_i = \dfrac{9 \times 10^9 \times (2.0 \times 10^{-4})^2}{0.1}$

$U_i = \dfrac{9 \times 10^9 \times 4.0 \times 10^{-8}}{0.1} = 3600 \text{ J}$

When the separation becomes very large, the potential energy becomes zero and is entirely converted into the kinetic energy of the two particles.

By conservation of mechanical energy:

$U_i = K_f$

$3600 = \dfrac{1}{2}mv^2 + \dfrac{1}{2}mv^2 = mv^2$

$3600 = (10 \times 10^{-3}) v^2$

$v^2 = \dfrac{3600}{10^{-2}} = 360000$

$v = 600 \text{ m/s}$