A 43 kg skier skis directly down a frictionless slope angled at 10° 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 1.4 m/s2, and (c) increasing at a rate of 2.8 m/s2.