Final answer:
Insufficient information is provided to calculate the magnitude of the electric field at a distance of 0.18m; the charge value is required for calculation using Coulomb's law.
Step-by-step explanation:
To calculate the magnitude of the electric field at a distance of 0.18m, not enough information is provided in the question. Typically, to calculate the electric field (E) due to a point charge, you would use Coulomb's law: E = k*q/r^2, where k is Coulomb's constant (8.99 x 10^9 Nm^2/C^2), q is the charge, and r is the distance from the charge. The newtons (N) are the unit of the electric field's magnitude. However, without the value of the charge (q) creating the field, the question cannot be answered. To complete this calculation, the value of the charge placed at the height h = 0.18m would be necessary.