I don't mind spending a long time on this question. I want a correct and detailed answer.
6. [15] Tipler & Mosca (6th ed) Chapter 26, Problem 60: A non-uniform, non-conducting thin disk of mass m, radius R, and total charge Q has a charge per unit area σ that varies as σ = (σ_0/R) and a mass per unit area μ that is given by μ = (m/Q)σ. The disk rotates with angular speed ω about its central axis. (b) Show that the magnetic moment μ and angular momentum L are related by L = 2μM.