Question

In a Geiger-Marsden experiment, calculate the distance of the closest approach to the nucleus of Z = 80, when an α- particle of 8 MeV energy impinges on it be{ore it comes momentarily to rest and reverses its direction.

How will the distance of the closest approach be affected when the kinetic energy of the α-particle is doubled ?

Answer 1

If KE becomes twice then r'₀ = r₀ / 2,

i.e. the distance of closet approach becomes half.