1. The problem statement, all variables and given/known data The square loop shown below is made up of four identical wires of length scripted l = 18 cm each charged with a linear density λ = 18 nC/m. Find the magnitude of the electric field at a distance z = scripted l/2 above the center of the loop. 2. Relevant equations Start by first simplifying the result from problem 21-46, E = (2kλ)(L/x)(4x2 + L^2)^-1/2 where x = (z^2 + (L/2)^2)^1/2. Then make use of the symmetry of the situation. 3. The attempt at a solution I used this equation to solve and got 335.53967, But I don't know what to do after this, or if this number is even right. Help please!