The work done to pull the sled up to the hill is given by
[tex]W=Fd[/tex]
where
F is the intensity of the force
d is the distance where the force is applied.
In our problem, the work done is [tex]W=1900 J[/tex] and the distance through which the force is applied is [tex]d=400 m[/tex], so we can calculate the average force by re-arranging the previous equation and by using these data:
[tex]F= \frac{W}{d}= \frac{1900 J}{400 m} = 4.75 N \sim 5 N [/tex]
