I would do this:
∫ A r^2 dr = A ∫ r^2 dr
That would give me this:
(1/3)A r^3
Integrating again treating A as a constant would then give me this:
(1/3)A ∫ r^3 dr = (1/12)A r^4
I could then set λ = (1/12)A r^4 , and I could substitute λ into the equation: e0 E(2π r L)...
Homework Statement
A long, non conducting, solid cylinder of radius 4.2 cm has a nonuniform volume charge density ρ = Ar^2, a function of the radial distance r from the cylinder axis. A = 2.5 µC/m5.
(a) What is the magnitude of the electric field at a radial distance of 3.2 cm from the axis...