A current of 2 A is passing through a metal wire of cross-sectional area $2 \times 10^{-6} \, \text{m}^2$. If the number density of free electrons in the wire is $5 \times 10^{26} \, \text{m}^{-3}$, the drift speed of electrons is (given $e = 1.6 \times 10^{-19} \, \text{C}$).