Example $23-8$ depicts the following scenario. The lightbulb in the circuit shown below has a resistance of $14$ and consumes $5\mathrm{.}0$ W of power; the rod is $1\mathrm{.}10$ m long and moves to the left with a constant speed of $3\mathrm{.}1$ m$/$s$,$ the strength of the magnetic field is $2\mathrm{.}5$ T$.$

What external force is required to maintain the rod a speed of $3\mathrm{.}32$ m$/$s$,$ everything else remaining the same?