College Physics 10th Edition by Raymond Serway,Chris Vuille

Exercise 75

In Rutherford's famous scattering experiments that led to the planetary model of the atom, alpha particles (having charges of +2 e and masses of 6.64 × 10 27 kg) were fired toward a gold nucleus with charge +79 e. An alpha particle, initially very far from the gold nucleus, is fired at 2.00 × 10 7 m/s directly toward the nucleus, as in Figure P16.23. How close does the alpha particle get to the gold nucleus before turning around Assume the gold nucleus remains stationary.