1. The problem statement, all variables and given/known data Two horizontal plates connected to 600v with the positive at the top. A positively charged ion between the plates moves downwards under the force of the field (neglect gravity). The ion has charge 1.6×10^–19C and mass 2.3×10^–26kg. Show that the kinetic energy of the ion is 4.8x10-17 J at the instant that it reaches the bottom plate. 2. Relevant equations KE = eV 3. The attempt at a solution eV = 1.6x10^-19 x 600 = 9.6x10^-17 J. This is exactly twice the number I am trying to reach and I can't get any further. The problem is that I don't understand the significance of the ion reaching the bottom plate. Thanks.