Sample Problem Electric potential
Electrons are continually being knocked out of air molecules in he atmosphere by cosmic-ray campaniles coming in from space. Once released. each electron experiences an electrostatic force F due TO the electric field if that is produced in the atmosphere by charged campaniles already on Earth. Near Earth s surface the electric field has the magnitude E = 150 N/C and is directed downward. What is the change !lU in the electric potential energy of a released electron when the electrostatic force causes it to move vertically upward through a distance d = 520 m SOLUTION We need three Key Ideas here. One is that the change fl U in the electric potential energy of the electron is related to the work.