Consider the inelastic collision e- + e^- → e^- + e^- + e^- + e⁺ in which an electron-positron pair is produced in a head-on collision between two electrons moving in opposite directions at the same speed. This is similar to Figure 36.39, but both of the initial electrons are moving.
a. What is the threshold kinetic energy? That is, what minimum kinetic energy must each electron have to allow this process to occur?
b. What is the speed of an electron with this kinetic energy?