A proton is released from rest at point A in a constant electric field and accelerates to point B (see part a of the drawing). An electron is released from rest at point B and accelerates to point A (see part b of the drawing). How does the change in the proton's electric potential energy compare with the change in the electron's electric potential energy? 

(a) The change in the proton's electric potential energy is the same as the change in the electron's electric potential energy. 

(b) The proton experiences a greater change in electric potential energy, since it has a greater charge magnitude. 

(c) The proton experiences a smaller change in electric potential energy, since it has a smaller charge magnitude. 

(d) The proton experiences a smaller change in electric potential energy, since it has a smaller speed at B than the electron has at A. This is due to the larger mass of the proton. 

(e) One cannot compare the change in electric potential energies because the proton and electron move in opposite directions.

Proton Electron