No ChatGPT or Ai please. Also, please answer the questions specifically. B here does not ask for momentum-- it asks for velocity.

reference: Griffiths Introduction to electrodynamics

Two concentric spherical shells are in a uniform magnetic field B = By z. The inner shell has radius a and a uniformly distributed charge (). the outer shell has radius b and a uniformly distributed charged @. Each shell is free to rotate aboutthe = axis and is initially at rest. a) The magnetic field is gradually turned off. Find the resulting angular momentum of the system. b) If @ = 0.1 Coulomb, @ = 10 cm and b = 20 cm, find the angular velocity of each shell, assuming M, =10 gm and M, = 40 gm