Charge 1 with a mass of 4 grams and a charge of +10 micro-coulombs is initially resting on a horizontal surface with friction. Charge 2 of +18 micro-coulombs is held in place 38 cm directly above charge 1. A third charge of -7 micro-coulombs is initially placed far from charge 1 directly to the left of charge 1. It is slowly brought closer to charge 1, at what distance will it begin to move charge 1 and overcome friction if the coefficient of static friction is 1.51? Answer in cm.