You have two disks, 1 and 2 , both of radius \(R=25.0 \mathrm{~mm}\) and both made of the same nonconducting material. Disk 1 carries a uniformly distributed charge \(q_{1}=1.50 \mu \mathrm{C}\), and the uniformly distributed charge \(q_{2}\) on disk 2 is unknown. You place disk 1 at \(z_{1}=0\) and disk 2 at \(z_{2}=+32.0 \mathrm{~mm}\) such that the symmetry axis of each disk coincides with the \(z\) axis. Using a small charged pith ball, you locate one position on the \(z\) axis where the electric force exerted on the pith ball is zero; this position is \(z_{F=0}=+88.0 \mathrm{~mm}\). What is the charge on disk 2 ?