Physics Homework Problem--Stuck? A 75 kg water skier is being pulled by a horizontal force of 495 N and has an acceleration of 2.0 m/s2. Assuming that the total resistive force exerted on the skier by the water and the wind is constant, what force is needed to pull the skier at a constant velocity? I tried doing this to solve the problem: F=ma F=75kg x 2.0= 150N Then I added 150 and 495 to get 645 N but this is not the right answer. Can someone please tell me what I did wrong?