In a Scattering Experiment,an Alpha Particle Initially with 8

Multiple Choice

In a scattering experiment,an alpha particle initially with 8.00 MeV of kinetic energy can approach the nucleus of an unknown element to within 20.0 fm.If the only force between the alpha particle and the nucleus of the unknown element is the electric force,then how close would it approach if its initial kinetic energy was 4.00 MeV instead?

A) 10.0 fm
B) 20.0 fm
C) 40.0 fm
D) 80.0 fm