Physics Question--Protons?

Question

A proton is shot directly at a nucleus of sulfur (Z= 16). If it gets to within about 7 x10^-15 m of this nucleus it will be so close as to be within the range of the nuclear force, and can initiate a nuclear reaction. What must be the initial kinetic energy (in MeV) that the proton must have to acheive this?

Thanks a lot!

Answer 1

KE = PE = kq1q2/r =  5.273E-13 J = 3.291 MeV