80. An infinitely long nonconducting solid cylinder of radius R has a nonuniform but cylindrically symmetrical charge distribution. The volume charge density is given by p(r) = c/r, where cis a positive constant having units C/m and ris the radial distance from the long central axis of the cylinder. (a) What is the charge in a section of the cylinder of length ? Write an expression for the electric field magnitude for (b) r R.

80. An infinitely long nonconducting solid cylinder of radius R has a nonuniform but cylindrically symmetrical charge distribution. The volume charge density is given by p(r) = c/r, where cis a positive constant having units C/m and ris the radial distance from the long central axis of the cylinder. (a) What is the charge in a section of the cylinder of length ? Write an expression for the electric field magnitude for (b) r R.