A 2.12 x 109 C charge has coordinates x = 0, y = -2.00; a 2.85 x 109 C charge has coordinates x = 3.00, y = 0; and a -5.40 x 109 C charge has coordinates x = 3.00, y = 4.00, where all distances are in cm. Determine magnitude and direction for the electric field at the origin and the instantaneous acceleration of a proton placed at the origin. (a) Determine the magnitude and direction for the electric field at the origin (measure the angle counterclockwise from the positive x-axis). magnitude 64231 N/C direction 100 (b) Determine the magnitude and direction for the instantaneous acceleration of a proton placed at the origin (measure the angle counterclockwise from the positive x-axis). magnitude direction