1. The problem statement, all variables and given/known data Ignore B & C for now The block in the figure reaches a velocity of 40 m/sec in 100 m, starting from rest. Compute the coefficient of kinetic friction between the block and the ground. W = 100N F = 40 N 2. Relevant equations ∑Fy = 0 so Normal Force = Weight ∑Fx = Force - Inertia - Frictional Force - Weight = 0 3. The attempt at a solution 0.5 (V^2 -Vo^2) = as 0.5 (40^2 - 0) = a(100m) a = 8 m/s^2 So I got this equation: 40 N = 100 N ( cos90) + 100N (8m/s^2 / 9.806 ) + 100 N ( μ) I ended up getting a negative coefficient of friction which is -0.415827. Is there something wrong with my equation?