F₁ = k * q₁ * q₂ / (ε₁ * R²)
F₂ =k * q₁ * q₂ / (ε₂ * (R/2)²)
F₂ / F₁ = ε₂ * (R/2)² / (ε₁ * R²) => F₂ = F₁ * ε₂ * (R/2)² / (ε₁ * R²)
F₂ = 7,8 Н * 81 / (4 * 2,1) ≈ 75 Н
F₁ = k * q₁ * q₂ / (ε₁ * R²)
F₂ =k * q₁ * q₂ / (ε₂ * (R/2)²)
F₂ / F₁ = ε₂ * (R/2)² / (ε₁ * R²) => F₂ = F₁ * ε₂ * (R/2)² / (ε₁ * R²)
F₂ = 7,8 Н * 81 / (4 * 2,1) ≈ 75 Н