1. The problem statement, all variables and given/known data Problem: A 10 kg box slides down a hill and has a constant velocity. The angle of the hill is 10° with respect to the horizontal. What is the coefficient of kinetic friction between the surface of the hill and the box? 2. Relevant equations Fn = mg + ma ƒk = μk * Fn 3. The attempt at a solution To calculate the coefficient of kinetic friction I used the formula ƒk = μk Fn and isolated μk to be μk = ƒk / Fn Where ƒk is kinetic frictional force, μk is the coefficient of kinetic friction, and Fn is the normal force. I don't have any of these variables, so I drew a free-body diagram and tried to find my normal force by doing: ∑Fy = Fn + mg cos 10° = 0 Fn = mg cos 10° Fn = (10 kg) (9.80 m/s^2) cos 10° = 96.5 N My problem is I am not sure on how to determine my kinetic fricitonal force ƒk to plug it into the μk = ƒk / Fn. Someone please guide me?