Yes, but the question asks what the initial energy of the particle would have to be when it is within 4.7 * 10^-15 m of a gold nucleus. It also states that 4.7 * 10^-15 is the radius of the gold nucleus. Therefore, the distance from the centre of the gold nucleus to the alpha particle is 2(4.7 *...
Homework Statement
Ernest Rutherford in his lab at McGill University, Montreal, fired alpha particles of mass 6.64 * 10^-27 kg at gold foil to investigate the nature of the atom. What initial energy must an alpha particle (charge +2e) have to come within 4.7 * 10^-15 m of a gold nucleus...