Question

The respective charges on three identical metal spheres (q1, q2 and q3) are ̶ 16.9 µ C,
5.60 µ C and 2.6 µ C. The spheres are brought together so that they touch each other,
and are then separated and placed on the x and y axes.
Calculate the net electrostatic force exerted on the sphere that is located at the origin
q1 is at origin, q2 is at (5.3mm,0), q3 is at (0,5.3mm)

Answer 1

charge on each after touching =1/3 (-16.9+5.6+2.6)e-6 C = Q
so now, you have two forces (q1q2, q1,q3) at right angles

force from each: kQ^2/.0053^2

so the net force (right angles) is sqrt(2F^2)=Fsqrt2=kQ^2/.0053^2 * sqrt2