Two positively-charged balls are tied together by a string. one ball has a mass of 30g and a charge of 1.?

two positively-charged balls are tied together by a string. one ball has a mass of 30g and a charge of 1. the other has a mass of 40g and a charge of 2. the distance between them is 5 cm. the ball with the smaller charge has a mass of 30g.the other ball has a mass of 40g. initially they are at rest, but when the string is cut they move apart.when they are a long way away from each other, how fast are they going?