A circular arc has a uniform linear charge density of -7 nC/m. The value of the Coulomb constant is 8.98755 * 10^9 N*m^2/ C^2. What is the magnitude of the electric field at the center of the circle along which the arc lies? The radius of the arc is 2.5 m and it goes counterclockwise 243 degrees around the center, starting at the positive x axis.