[Physics for University Beginners Vol 2] [Electrostatics] 11.15. between the two points is 400 V, what is the speed of the proton when it passes through point Y? The A proton moves in an electric field from point X to point Y. If the potential difference 1.6 x 10-19 C, mass of proton speed of the proton at point X is 4.5 x 105 m/s. (Charge on a proton = 1.67 x 10-27 kg) =​