Before the advent of solid$-$state electronics, vacuum tubes were widely used in radios and other devices. A simple type of vacuum tube known as a diode consists essentially of two electrodes within a highly evacuated enclosure. One electrode, the cathode, is maintained at a high temperature and emits electrons from its surface. A potential difference of a few hundred volts is maintained between the cathode and the other electrode, known as the anode, with the anode at the higher potential. $($

Suppose a diode consists of a cylindrical cathode with a radius of $\backslash (6\mathrm{.}200\backslash$times $10^\{-2\}\backslash$mathrm$\{$~cm$\}\backslash ),$ mounted coaxially within a cylindrical anode with a radius of $0\mathrm{.}5580$ cm $.$ The potential difference between the anode and cathode is $265$ V $.$ An electron leaves the surface of the cathode with zero initial speed $\backslash (\backslash$left$($v$\_\{\backslash$text $\{$initial $\}\}=0\backslash$right$)\backslash ).$ Find its speed $\backslash ($ v$\_\{\backslash$text $\{$final $\}\}\backslash )$ when it strikes the anode.

Figure $1)$