Practice question

**Coulomb's law** gives force between point charges as F = k·|q₁q₂|/r², k = 1/(4π ε₀) = 9×10⁹ N·m²/C², directed along line joining charges. Like charges repel, opposite attract, magnitude scales with product of charges and inverse square of separation r². Let x be distance from +14 μC , then 1 - x from -6 μC . (14 × 10⁻⁶/x²) = (6 × 10⁻⁶/(1 - x)²) , 14 (1 - x)² = 6 x² . 14 (1 - 2 x + x²) = 6 x² , 14 - 28 x + 14 x² = 6 x² . 8 x² - 28 x + 14 = 0