A disk has radius R = 1.20 cm. Its surface charge density is 1.70 x 10-6 C/m2 from r = 0 to r = R/2 and 9.10 x 10-7 C/m2 from r = R/2 to r = R.
(a) What is the total charge (in C) on the disk?
(b) With V = 0 at infinity, what is the electric potential (in V) at a point on the perpendicular central axis of the disk, at distance z = R/2 from the center of the disk?