What is the distance of closest approach to the nucleus of an `alpha`partile which undergoes scattering by `180^(@)` is geiger-marsden experiment?

What is the distance of closest approach to the nucleus for an alpha -particle of energy 5 MeV which undergoes scattering in the Gieger-Marsden experiment.

What is the distance of closest approach to the nucleus for an alpha -particle of energy 5J MeV which undergoes scattering in the Gieger-Marsden experiment.

In a Geiger-Marsden experiment, what is the distance of closest approach to the nucleus of a 7.7 MeV a-particle before it comes momentarily to rest and reverses its direction?

In a Geiger-Marsden experiment, what is the distance of closest approach to the nucleus of a 7.7 MeV a-particle before it comes momentarily to rest and reverses its direction?

In a geiger - marsden experiment. Find the distance of closest approach to the nucleus of a 7.7 me v alpha - particle before it comes momentarily to rest and reverses its direction. (z for gold nucleus = 79) .