1. The problem statement, all variables and given/known data A boy drags his sled of 90.0N at a constant speed up a 18 degree hill. He pulls with a 40.0N force on a rope which is 35 degrees above the horizontal. a) What is coefficient of kinetic friction between the sled and the snow? 2. Relevant equations Coefficieint = Force of Kinetic Friction / Normal Force 3. The attempt at a solution I can find the normal force, no problem. It's just the kinetic friction I'm having trouble finding. I would think that the kinetic friction would be whatever the x component of the force applied is, since that is what is opposing the sled. However, if that was true, the Force net of the x prime would be 0. How would this be the kinetic friction then? Wouldn't it be for static since there is no movement? I thought of doing this and checked yahoo answers, a response had a similar method. I just don't understand why to do this though.