1. The problem statement, all variables and given/known data Protons are accelerated by an electric field passing through a hole in the anode and accelerated towards the cathode (to the right) A proton passes through the anode at 6.2 × 105 m s–1, and passes through the cathode at 8.8 × 105 m s–1. Show that the strength of the electric field is 100 000 V m–1. 2. Relevant equations Ek= 1/2mv^2 and Ep=Eqd 3. The attempt at a solution Usually we get problems like this when the charged particle is forced to the plate with the same charge thus it gains electric potential. Then the charged particle is released and accelerates towards the plate with the opposite charge so electric potential lost= kinetic energy gained when particle reaches the other plate. But for this question Ep(lost)=Ek(gained) doesn't seem to apply. I thought it might be Ep at anode was Ek but I'm kinda confused.