1. The problem statement, all variables and given/known data A 64 microC charge is locate 30 cm to the left of a 16 micro C charge. What is the resultant force on a -12 micro C charge positioned exactly 50 mm below the 16 micro C charge? 2. Relevant equations coulomb law f=k*qq/(r^2),resultant force,resolve into x and y component. 3. The attempt at a solution the first three steps are straightforward first step using Pythagoras rule gives s=58.3 mm and theta = 59.0 degree the force b/w q1 and q2 using coulomb law i calculated F13 = 2033 N. similarly ,the force between q2 and q3, gives correctly F 23= 691 N. i am having trouble understanding these steps about resolving it into components.i need some revision here. Fx = 0- F13 cos 59.0 (where does the zero come from?) = -(2033 N) cos 59.0 which gives Fx = -1047 N also Fy = F23 + F13 sin 59.00(why add force 23) = 691 N + (2033 N) sin 590 Fy = 2434 N i can do the rest.