A uniform insulator of charge dq shaped like a very thin tube that is curved into semicircle of radius r, shown at near right, creates an electric field at its center of curvature at point P that has magnitude d = 2k dq r A uniformly charged insulated semicircular half-ring has inner radius R = 10 cm, and outer radius R = 20 cm, as shown far right. The total charge of the half-ring q = -20 C. 1) What force would act on a point charge q = -5 C located at point P? West Up + Down P.- East R R