5. (9 points) Consider the half-circle of charge Half-circle of charge 4 y shown. The half-circle is very thin, and has linear charge density 1. For this problem use the convention Infinitesim that the potential is 0 at infinity. charge dq (a) The infinitesimal charge dq spans an angle do. Give an expression for dq in terms of a, 1, and do. (2 pts) P (b) What is the magnitude of the infinitesimal potential dV due only to the infinitesimal charge dq. You answer should be in terms of 1, a, do, and ke (or co) (4 pts) (c) Integrate to find the total potential at P due to this half-circle of charge in terms of the variables above. (3 pts)