Friction Problem!! A Man dragged a 51 Kg bag at a 45 degree angle with a force of 400 N. The bag moved along hte pavement with a constant speed. What is the coefficient of static friction? OK SO, you can make a triangle and figure out that 283 N are pulling horrizontal and 283 pulling vertically. But im not sure how to plug any of that into the F=(Friction coef)N where F is force of friction, and N is normal force... How do i find the coeff. of static fricton? Another one that is similar is the following: In grass-skiing, a man goes down at 92 Km/hr. It takes him 6.6 to reach that speed from rest at a 35 degree incline. His mass is 75 Kg. What is the coeffcient of friction between the grass and his skis that day? I'm totally lost....help please!?