A pith ball of mass 0.20 grams and charge -3.0 nC hangs from an insulating thread and is repelled by the charged metallic sphere of a Van de Graaff generator. It is noted that the thread is tilted by 17 deg when the pith ball hangs at rest 0.30 m from the center of the sphere. Determine the electric field at that position.

A pith ball of mass 0.20 grams and charge -3.0 nC hangs from an insulating thread and is repelled by the charged metallic sphere of a Van de Graaff generator. It is noted that the thread is tilted by 17 deg when the pith ball hangs at rest 0.30 m from the center of the sphere. Determine the electric field at that position.