Two Extremely Large Nonconducting Horizontal Sheets Each Carry Uniform Charge

Short Answer

Two extremely large nonconducting horizontal sheets each carry uniform charge density on the surfaces facing each other. The upper sheet carries +5.00 µC/m². The electric field midway between the sheets is 4.25 × 10⁵ N/C pointing downward. What is the surface charge density on the lower sheet? (ε0 = 8.85 × 10^-12 C²/N ∙ m²)