Into the region of space between the plates of a parallel-plate capacitor there Ilies (a) an electron and (b) a negatively charged ion with a velocity directed parallel to the plates. Both the electron and the ion have rec.eived their initial kinetic energy by passing the same potential difference `U_0` and the potental difference across the capacitor is U. The distance between the plates is d. Which of the two particles will travel a greater distance before hitting the positively charged plate if both fly into the capacitor at a point that is exactly in the middle of the distance between the plates?