Aplastic spring with spring constant 850 n/m has a relaxed length of 0.100 m. the spring is positioned vertically on a table, and a charged plastic 1.00-kg sphere is placed on the top end of the spring. another charged object is suspended above the sphere without making contact. if the length of the spring is now 0.0950 m, what are the magnitude and direction of the electric force exerted on the sphere?