1. The problem statement, all variables and given/known data In outer space, a ball with mass 0.25kg and charge +4/K C is shot from 5m towards a +0.5C charged ball with an initial velocity of 20 m/s What main Physics principle should be used to solve this problem? What is the closest the small ball will get to the large one? What is the velocity and acceleration at this position? 2. Relevant equations F=ma vf=v0+2ax F(electric) = KQq/r^2 where K = 9*10^9 Nm^2/C^2 3. The attempt at a solution I should use Newton's Second Law because by using F = ma, I could find a, then substitute into the 1D equation for displacement to solve for how far the 0.25kg ball travels. I got a=F/m = -0.32 m/s^2 and substituted into the equation vf=v0+2ax (I made vf=0) to find x. My answer was 625 m which is not reasonable. I couldn't find the answer without a correct answer from the second question.