minimum separation

fa08ti

two frictionless pucks are placed on a level surface, as shown, at an initial distance of 20.0 m. the mass of puck 1 is 0.80 kg and it has a charge of +3.0 X 10^-4 C., while puck 2 is 0.40 kg with a charge of +3.0 X 10^-4 C. the initial velocity of puck 1 is 12.0 m/s (E) and the initial velocity of puck 2 is 8.0 m/s (W). find the minimum separation of the two pucks (the minimum distance between the pucks>

1: i'm totally lost
would i use
E= delta V/r
?

gneill

Which forms of energy are at play? How do they relate to each other?