A long, nonconducting, solid cylinder of radius 3.8 cm has a nonuniform volume charge density ? that is a function of the radial distance r from the axis of the cylinder, as given by Ar2, with A = 2.6 µC/m5.
(a) What is the magnitude of the electric field at a radial distance of 2.8 cm from the axis of the cylinder?
(b) What is the magnitude of the electric field at a radial distance of 4.8 cm from the axis of the cylinder?