9. Two point charges of +5.0C and -2.0C are fastened to a table 1.0 m apart. Where should we place a positive point charge qs so that it would be in equilibrium? (a) Draw a sketch. Where would you place +q3, in the region A (left), B (between) or C (right) to cancel the forces? How will you define the unknown distance x? (b) Draw a free-body diagram for q3. Let F31, F32 be the forces on q: due to q and q, respectively. (c) Using Coulomb's law, express F31 and F32 in terms of the given variables. F31 = k, etc. Make sure you get the distances right. k = 9x10 Nm/C (d) Set {Fnet = 0 Note that F31 is repulsive (+) and F32 is attractive (-). (e) Simplify and obtain the resulting quadratic as -b+b-4ac ax+bx+c = 0. Solve for x using x= 2a A +5 q1 B 1m -2 92