Resources Ck Give Up? Feedback A uniform electric field of 3.00 kN/C points in the +x-direction. What is the change in potential energy U electric,b - U electrica of a +2.00 nC test charge as it is moved from point a at x = -30.0 cm to point b at x = 50.0 cm? Uelectric,b - electrica Incorrect The same test charge is released from rest at point a. What is its kinetic energy K; when it passes through point b? Kb Incorrect If a negative charge instead of a positive charge were used in this problem, qualitatively how would your answers change? (Select all that apply.) electric potential energy magnitude increases kinetic energy magnitude increases kinetic energy magnitude decreases electric potential energy magnitude decreases electric potential energy changes sign test charge never passes through point b kinetic energy changes sign