For this case we have the following equation:
w = F • PQ
Where,
w: work done
F: is the force vector
PQ: is the vector of the direction of movement.
Rewriting the equation we have:
w = || F || • || PQ || costheta
Substituting values:
w = (60) * (100) * (cos (45))
w = (60) * (100) * (root (2) / 2)
w = 4242.640687 lb.ft
Answer:
The work done pushing the lawn mower is:
w = 4242.6 lb.ft