Answer:
961 N/C to the left
Explanation:
The magnitude of the electric field due to an infinite non-conducting sheet is:
E = σ / (2ε₀),
where σ is the surface charge density (C/m²),
and ε₀ is the free space permittivity (8.85×10⁻¹² C²/(Nm²)).
The direction of the field is away from positive charges and towards negative charges.
σ₁ has a negative charge, so the electric field due to σ₁ will be to the left (-x direction).
σ₂, σ₃, and σ₄ have positive charges, so the electric field due to those surfaces will be to the left (-x direction).
The total electric field at A is therefore:
E = 1 / (2 × 8.85×10⁻¹² C²/(Nm²)) (-6×10⁻⁹ C/m² − 5×10⁻⁹ C/m² − 2×10⁻⁹ C/m² − 4×10⁻⁹ C/m²)
E = 5.65×10¹⁰ Nm²/C² (-5×10⁻⁹ C/m²)
E = -961 N/C