You pull your sled through the snow a distance of 500 meters with a horizontal force of 200 newtons. How much work did you do? Because the snow suddenly gets too slushy, you decide to carry your 100 newton speed the rest of the way home. How much work do you do when you pick up the sled, lifting it .5 meters upward? How much work do you do to carry the sled if your house is 800 meters away?

there are no contact forces mentioned on the list of choices that you've provided.

when jerome paddle in flowing river towards east the net speed of jerome will increase

so the net speed of jerome will be given as

now the speed of paul will be same as it is given as he is running on the ground

so

so here we can say since the speed of jerome is more so he will win the race

now as we know the distance so the time difference is given as

so jerome will reach first and the time difference will be 203.55 s or 3.4 min