Two charges of equal magnitude of 2C and mass of 1.0 g are separated by a distance of 3 mm. Find the velocity of one particle when they are separated by a distance of 4mm.

Answer 1

Are both particles free to move? Was the velocity 0 when they were 3 mm apart?

If so, they move at equal velocity in opposite directions. Use conservation of energy and the change in electrostatic potential energy to compute the increase in kinetic energy.

kQ^2/0.003m - kQ^2/0.004m = 2*(1/2) M V^2

M = 0.001 kg
k is the Coulomb constant