An alpha particle with charge + 2e and mass 6.64 10 × −27 kg is fired from far away towards a gold nucleus with an initial speed of 2.49 10 × +7 m/s. If the distance of closest approach between the alpha particle and gold nucleus is 1.77 × 10−14 m, calculate the charge of the gold nucleus to 2 significant figures, in terms of e. You may assume the gold nucleus remains at rest during the motion of the alpha particle.