You and your team are designing a device that can be used to position a small, plastic object in the region between the plates of a parallel-plate capacitor. A small plastic sphere of mass m = 1.20 × 10⁻² kg carries a charge q = +0.200 μC and hangs vertically (along the y direction) from a massless, insulating thread (length l = 10.0 cm) between two vertical capacitor plates. When there is no electric field, the object resides at the midpoint between the plates (at x = 0). However, when there is a field between plates (in the ±x direction) the object moves to a new equilibrium position.

(a) To what value should you set the field if you want the object to be located at x = 2.10 cm?

(b) To what value should you set the field if you want the object to be located at x = −3.30 cm?