Question

if a helium nucleus with a mass of 6.68x10^-27 kg, a charge of +2e, and an initial velocity of 1.5x10^7 m.s is projected head-on toward a gold nucleus with a charge of +79e, how close will the helium atom come to the gold nucleus before it stops and turns around?

Answer 1

This happens when all kinetic energy is potential energy (that's when \(|v|=0\)). Treat the gold nucleus as a potential well, and use conservation of energy to solve the problem.

Answer 2

Do you need a further hint?