A spark plug in a car's engine creates a spark by charging up an electrode so much that the electric field in the surrounding gas/air mixture exceeds the "dielectric strength" of the gas/air mixture. The electrode gradually wears to a spherical shape, so we can model this problem as an isolated, charged, metal sphere of diameter 1.8-mm. Part A Find the minimum potential (relative to infinity) for an isolated, charged, metal sphere (with diameter as given in the introduction) such that it will create a spark. Assume the dielectric strength of the gas/air mixture surrounding the sphere is 3 MV/m. Express your answer using two significant figures.