A constant electric field accelerates a proton from rest through a distance of 1.55 m to a speed of 1.65 x 105 m/s. (The mass and charge of a proton are mp 9p = e = 1.60 x 10-19 C.) HINT (a) Find the change in the proton's kinetic energy (in J). (b) Find the change in the system's electric potential energy (in J). ] (c) Calculate the magnitude of the electric field (in N/C). N/C 1.67 x 10-27 kg and