A flat copper ribbon 0.330 mm thick carries a steady current of 58.0 A and I5 located in a uniform 1.40 T magnetic eld directed perpendicular to the plane of the ribbon. If a Hall voitage of 9.60 mi is measured across the ribbon, what is the charge density of the free electrons? 1.6e29 y m'3 What effective number of free electrons per atom does this result indicate? \\:|