1. The problem statement, all variables and given/known data 1) http://i.imgur.com/JbK13.gif The figure below depicts the forces acting on a safe being pushed up an ramp by movers, Fa. The mass of the safe is 500 kg, the coefficient of static friction along the incline is μs = 0.41 and the coefficient of kinetic friction along the incline is μk = 0.34. The ramp forms an angle θ = 23° above the horizontal. The top of the wall is h = 1.0 m off the floor. What force needs to be applied to hold the safe in place? 2) http://i.imgur.com/ZTYbR.gif A young boy with a broken leg is undergoing traction. Find the magnitude of the total force of the traction apparatus applied to the leg, assuming the weight of the leg is 75 N and the weight hanging from the traction apparatus is also 75 N, θ = 28°. 2. Relevant equations None were given to me, but this is what I think they are: 1)Fs = μs * N w = mg 2) horizontal component of the traction force = 2 * 75 * cos (28) = 132 N 3. The attempt at a solution 1) static friction cannot hold the safe in place without having it slide back down x components: -mg sin(theta) + Ffr = 0 = mg sin(theta) + uN y components: N - mg cos(theta) = 0 N = mg cos(theta) therefore F = -mg sin(theta) + u(mg cos(theta)) I don't think this is right... 2) horizontal component of the traction force = 2 * 75 * cos (28) = 132 N magnitude of the force exerted on the femur by the lower leg = 132 N I really appreciate any help you can give me! Thank you so much!