56. The figure shows a graph of electric potential versus position along the x-axis. A proton is originally at point A, moving in the positive x-direction. How much kinetic energy does it need to have at point A in order to be able to reach point E ( with no forces acting on the proton other than those due to the indicated potential)? Points B, C, and D have to be passed on the way. 57. Repeat Problem 56 for an electron rather than a proton. VA D (150.0 V) A (100.0 V) E (55.0 V) B (OV) C (-60.0 V) Problems 56 and 57