An alpha particle (charge +2e) enters a uniform electric field E= 5x10^4 v/m m directed along,say, the +y axis. The particle moves freely through a displacement s = y = 0:50 m in the direction of the field.
(a) Find the dierence in the electrical potential, V , that the particle moves through.
(b) Find the change in the potential energy, U of the particle as it moves through this displacement.
(c) What is the physical meaning of the sign? Does it gain or lose K.E.?