An alpha particle , which is the same as a helium-4 nucleus, is momentarily at rest in a region of space occupied by an electric field. The particle then begins to move. Find the speed of the alpha particle after it has moved through a potential difference of -3.45×10^-3 V . The charge and the mass of an alpha particle are = 3.20×10^-19 C and = 6.68×10^-27 kg , respectively. What is the value of the change in potential energy, , of the alpha particle?