Problem $3$: Classical Theory of Conduction

How long would it take for an electron to travel through the grounding cable from the roof of a house to

the ground $($~$10$ m$)$ if a $300$ kV lightning bolt hit the roof. Assume the cable uses #$4$ Cu wire $(5\mathrm{.}2$ mm

dia$)$ with resistivity of $1\mathrm{.}7$ cm and carrier density of $8\mathrm{.}51022$ cm$3.$

Note: In order to find the travel time t$,$ calculate the electron drift velocity vd divided by the distance over

which the electron travels.