To practice problem-solving strategy 21.1 coulomb's law. three charged particles are placed at each of three corners of an equilateral triangle whose sides are of length 2.3 cm . two of the particles have a negative charge: q1 = -6.7 nc and q2 = -13.4 nc . the remaining particle has a positive charge, q3 = 8.0 nc . what is the net electric force acting on particle 3 due to particle 1 and particle 2?