A copper wire has a circular cross section with a radius of 2.50 mm. (a) If the wire carries a current of 3.50 A, find the drift speed of the electrons in the wire. (Assume the density of charge carriers (electrons) in a copper wire is n = 8.46 1028 m/s (b) All other things being equal, what happens to the drift speed in wires made of metal having a larger number of conduction electrons per atom than copper? Explain. electrons/m.)