A point charge q1 = -8.9 μC is located at the center of a thick conducting shell of inner radius a = 2.2 cm and outer radius b = 4.5 cm, The conducting shell has a net charge of q2 = 1.1 μC.
What is σb, the surface charge density at the outer edge of the shell?
What is σa, the surface charge density at the inner edge of the shell?