PROBLEMS TO BE WRITTEN UP AND TURNED IN AT RECITATION

     This problem is due at your first recitation meeting after Wed 09/24.
     The problem should be written on a single sheet of paper (front and back), 
     or if multiple sheets are used, staple them together.  For full credit,
     the work must be neat, with clearly labeled diagrams.  The labels must
     be in BOTH words and symbols.  For each part of each problem, you must 
     BRIEFLY explain your strategy in words, as well as neatly showing your 
     physics equations and math, with proper units. (20 points, 10 for each
     part)

         E2.  An infinitely long rod of radius R carries a uniform
              volume charge density rho (rho > 0).
              (a) Show how to use Gauss' Law to prove that the
                  electric field inside this rod points radially
                  outward and has magnitude 

                            E = (rho*r)/(2*epsilon_0).
               
              (b) Integrate the electric field over an appropriate
                  displacement to find the potential difference from
                  the rod's surface to its axis.  State explicity
                  which of those two locations is at the higher
                  potential.