The work by Mark : 100 J
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
[tex]\tt W=F\times d[/tex]
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
[tex]\tt W=5\times 20\\\\W=100~J[/tex]