A 4 C and -7 C charge are separated by a horizontal line from left to right respectively by a distance of 4 m between each adjacent charge.
(a) What is the electric potential 3 meters to the right of the -7 C charge?
(b) What is the potential 6 meters to the right of the -7 C charge?
(c) What is the kinetic energy of an electron going from 3 to 6 meters?