a voltage difference of $100$v is placed across two parallel conductive plates. an initially stationary electron is released right next to the plate at low voltage and accelerates toward the plate at high voltage. how much has the electron's potential energy changed when it hits the other plate? what is the kinetic energy of the electron when it hits the other plate? what is the speed of the electron when it hits the other plate? when it hits the other plate, what fraction of the speed of light is the electron traveling at$?$