In a nuclear fusion experiment, alpha particles are directed at a stationary lithium target. A lithium nucleus has 3 protons, and an alpha particle has 2 protons.
During a specific head-on collision, the distance of closest approach achieved is 40.0 fm40.0\text{ fm}40.0 fm.
Which is the best estimate of the work done on an alpha particle as it moves from an initial distance of 120 fm120\text{ fm}120 fm to this point of closest approach?
10−16 J10^{-16}\text{ J}10−16 J
10−14 J10^{-14}\text{ J}10−14 J
10−12 J10^{-12}\text{ J}10−12 J
10−10 J10^{-10}\text{ J}10−10 J
