A uniformly charged rod (length L, charge density ) slides out the x axis at constant speed v. At time t = 0 the back

A uniformly charged rod (length L, charge density λ) slides out the x axis at constant speed v. At time t = 0 the back end passes the origin (so its position as a function of time is x = vt, while the front end is at x = vt + L). Find the retarded scalar potential at the origin, as a function of time, for t > 0. [First determine the retarded time t₁ for the back end, the retarded time t₂ for the front end, and the corresponding retarded positions x₁ and x₂.] Is your answer consistent with the Liénard-Wiechert potential, in the point charge limit (L vt, with λL = q)? Do not assume v c.