A uniform volume charge density of 80 C/m 3 is present throughout the region 8 mm <

A uniform volume charge density of 80 μC/m³ is present throughout the region 8 mm < r < 10 mm. Let ρ_ν = 0 for 0 < r < 8 mm.

(a) Find the total charge inside the spherical surface r = 10 mm.

(b) Find Dr at r = 10 mm.

(c) If there is no charge for r > 10 mm, find D_r at r = 20 mm.