It is 800 N FN = 600N + 200 N = 800 N Answer to your question: The net force is all Newton's second law. It is the force that acts on a body or a particle. for example: It is the force we make when we push a car or something heavy that is in a straight line. .
The answer is above but I don't know if it's correct.
the anwser is c is always the best anwser
"with the wind" is a tail-wind, and the speeds are added to get the groundspeed.
"against the wind" is a head-wind, and the windspeed is subtracted from the airspeed.
Power = Force * Distance/ time
P = 1,250 * 2/3
P = 2,500/3
P = 833.33 Watts
So, your final answer is 833.33 Watts