The work by Mark : 100 J
Further explanation
Work is the transfer of energy caused by the force acting on a moving object
Work is the product of force with the displacement of objects.
Can be formulated
![\tt W=F* d](https://img.qammunity.org/2021/formulas/chemistry/high-school/phx2gbecidew34i7kigq22615j89k4c2vw.png)
W = Work, J, Nm
F = Force, N
d = distance, m
Mark is using 5N to push the box 20 m,
F = 5 N
d = 20 m
![\tt W=5* 20\\\\W=100~J](https://img.qammunity.org/2021/formulas/chemistry/high-school/s9t316gzcf9t7u3f1yn2dmkbc09lf2nhxp.png)