11. A spherically symmetrical but non-uniform charge distribution is given by ρ(r) = ρ₀(1 − r/R) for r ≤ R; ρ(r) = 0 for r ＞ R, where ρ₀ = 10 μC/m³ and R = 0.250 m. What is the electric field produced by this charge at r = 0.500 m? ___(12)___ (N/C)