A snowboarder descends a hill with an incline of 50°. the coefficient of kinetic friction of the board on the snow is µ = 0.100. The mass of the snowboarder and board is 86 kg. The snowboarder starts at rest and ends up 390 meters down the slope. (a) What is the work done on the snowboarder by the force of friction (watch sign)? (b) What is the boarder's speed at the end of the course? Can anyone help me with this problem. I appreciate it.