A total amount of charge 0 is uniformly distributed along a thin semicircle of radius R. Show that the electric eld at a point P at the center of the circle is 73' 2 . Use a Riemann sum. (Hint: Recall that S = Re, so As its R439, or is = Rd . This problem is much easier ifwe use 9 as our variable of integration. Also note that if you get a really hard integral. you are either making the problem harder that it has to be, or you are doing it wrong.)