College Physics 10th Edition by Raymond Serway,Chris Vuille

Exercise 33

In a Rutherford scattering experiment, an a-particle (charge = +2 e ) heads directly toward a gold nucleus (charge = +79 e ). The -particle had a kinetic energy of 5.0 MeV when very far ( r ) from the nucleus. Assuming the gold nucleus to be fixed in space, determine the distance of closest approach. Hint: Use conservation of energy with PE = k e q 1 q 2 / r.