Three charges are arranged as shown in the figure below. Find the magnitude and direction of the electrostatic force on the charge q = 4.79 nC at the origin. (Let r12 = 0.256 m.) 0.100 m -3.00 nC 6.00 nC 112 x Step 1 The strategy to use when calculating the force exerted by a set of several point charges is to find first the forces exerted by each of the point charges individually. The force exerted by the entire set of charges is the net force resulting from the forces exerted by the individual charges. The forces from the individual charges in this problem are shown in the diagram below. y 9 0.100 m FR F3 93 92 112 The charge q exerts a repulsive force F12 on q as shown in the diagram. The distance separating these charges is 12 = 0.256 m so the magnitude of this repulsive force is given by the following equation where k is the Coulomb constant in SI units. F12 = ke 19111921 12 10-18 (2) (8.99 x 109 N m/c2) 0.256 m) x 10-6 N