1. The problem statement, all variables and given/known data Consider a very thin conducting ring of radius R which contains a total positive charge of +Q coulombs. (a) Derive a formula for the z coordinate which gives the maximum value for the magnitude of E ring (Z)? (b) Suppose that the charged ring is oriented horizontally, as shown in the diagram above right. Suppose that one wishes to levitate a ball with charge +Q coulombs above the charged ring. Derive a formula for the largest value for the mass M of a ball which can be levitated in this manner. The diagram is shown here http://www.chegg.com/homework-help/...itive-charge-q-coulombs-derive-formu-q1409271 3. The attempt at a solution I have no idea about how to start this question.