A straight, nonconducting plastic wire $8.50 \mathrm{~cm}$ long carries a charge density of $+175 \mathrm{nC} / \mathrm{m}$ distributed uniformly along its length. It is lying on a horizontal tabletop. (a) Find the magnitude and direction of the electric field this wire produces at a point $6.00 \mathrm{~cm}$ directly above its midpoint. (b) If the wire is now bent into a circle lying flat on the table, find the magnitude and direction of the electric field it produces at a point $6.00 \mathrm{~cm}$ directly above its center.