1. The problem statement, all variables and given/known data A 31 kg skier skis directly down a frictionless slope angled at 13° to the horizontal. Choose the positive direction of the x axis to be downhill along the slope. A wind force with component Fx acts on the skier. What is Fx if the magnitude of the skier's velocity is (a) constant, (b) increasing at a rate of 1.2 m/s2, and (c) increasing at a rate of 2.4 m/s2. 2. Relevant equations Newton's second law. 3. The attempt at a solution The velocity is constant hence acceleration tends to 0. The forces acting on the skier are the normal force, weight, and the wind force. In the first part, the net force is equal to 0, therefore the force (Fx) is -68.34 N. I attempted to do the second and third part. I assumed that the net force will be equal to the mass times the acceleration, which is 1.2 and 2.4 respective of the second and third parts. I found two values for Fx but the site and my instructor said they were wrong. I tried solving it many times and it gave the same answer.