A nine-volt battery is connected to a thin wire (r = 0.0005 m, length = 1.50 m) of unknown metal. A current meter indicates that the current flowing is 3.14 A. What is the resistivity of the wire? How thick would the wire have to be (radius) in order for the same amount of current to flow (3.14 A) if the wire were 6.00 m long?