PROBLEMS TO BE WRITTEN UP AND TURNED IN AT RECITATION

     This problem is due at your first recitation meeting after Tue 03/07
     (so you have two written HW problems due at these recitations).  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 the problem, you must 
     BRIEFLY explain your strategy in words, as well as neatly showing your 
     physics equations and math, with proper units. 


              HRW Problem Supplement #1 - CHAPTER 27 (10 points)

         10.  (a) The current density across a cylindrical conductor
              of radius R varies in magnitude according to the equation

                            J = J_0(1-(r/R))

              where r is the distance from the central axis.  Thus,
              the current density is a maximum J_0 at that axis (r=0)
              and decreases linearly to zero at the surface (r=R).
              Calculate the current in terms of J_0 and the
              conductor's cross sectional area A = (pi)R^2.
              (b) Suppose that, instead, the current density is a
              maximum J_0 at the cylinder's surface and decreases
              linearly to zero at the axis: 

                              J = J_0(r/R)

              Calculate the current.  Explain why the result is
              different from that in (a).