일반물리학 2 — Electric Fields: Problem 54

54 Figure 22-46a shows a circular disk that is uniformly charged. The central z axis is perpendicular to the disk face, with the origin at the disk. Figure 22-46b gives the magnitude of the electric field along that axis in terms of the maximum magnitude $E_m$ at the disk surface. The z axis scale is set by $z_s = 16.0 \text{ cm}$. What is the radius of the disk?