Luke does a work of 308Nm
If we have a constant force [tex]\vec{F}[/tex] that acts on a body in the same direction as the displacement [tex]\vec{s}[/tex], then the work [tex]W[/tex] is defined as the product of the force magnitude [tex]F[/tex] and the displacement magnitude [tex]s[/tex]. In other words:
[tex]W=Fs[/tex], which is valid for a constant force in direction of straight-line displacement.
In this problem:
[tex]F=22N \\ \\ s=14m[/tex]
Therefore:
[tex]W=22\times 14 \\ \\ \boxed{W=308Nm}[/tex]