Answer: 1,500 J
Explanation:
The work done by Luke is given by:
[tex]W=Fdcos \theta[/tex]
where
F = 65 N is the force applied by Luke
d = 25 m is the displacement of the sled
[tex]\theta=25^{\circ}[/tex] is the angle between the direction of the force and the displacement
Substituting numbers into the formula, we find
[tex]W=(65 N)(25 m)(cos 25^{\circ})=1473 J[/tex]
So, approximately 1500 J.