A copper wire of length 5 cm carries a current of density `j = 1 A (mm)^(-2)`. The density and molar mass of copper are `9000 Kg m^(-3) and 63 gmol^(-1)`. Each copper atom contributes one free electron. The temperature of the wire is `27^(@)C`. Estimate the (average) distance travelled by a free electron during the time it moves from one end of the copper wire to the other end. Assume that thermal motion of electrons are similar to that of molecules of an ideal gas.
