Electric Field Problems 10. Calculate the magnitude and direction of the electric field at a distance of 0.50 m to the right of a 550 mC charge. 11. A proton is placed in an electric field having a magnitude of 5.00 N/C. If the proton is released from rest, calculate the acceleration of the proton at the moment it is released. (Hint: Remember Newton's second law!) 12. A -10 mC is located at y = -.500 m. A +50 mC charge is placed at y = +.350 m. Calculate the electric field at the origin