a$)(2$ pts$)$ Consider a sphere with radius R$$that has a total charge Q$$uniformly distributed throughout its volume. $$The sphere spins at angular velocity omega$$about its center, which is at the origin. $$Find the volume current density J$($r$,$ theta, phi$).$

b$)(2$ pts$)$ Consider a very thin plastic ring that has a radius R$$and a constant linear charge density. $$The total charge on the ring is Q$.$The ring spins at an angular velocity omega$$about its center, which is at the origin. $$Find the current I.