1. The problem statement, all variables and given/known data Lindsey's car is driving up a hill when her book bag, which she forgot on the roof, falls off. The bag has a mass of 19kg and slides up the hill 60 meters from its initial speed of 20m/s to rest. If the hill climbs at an angle of 30 degrees then what was the coefficient of friction? 2. Relevant equations Fn = mgcosx Ff = [tex]\mu[/tex]cosx F = ma Vf2 = Vi2 + 2ad Fp = mgsinx (?) 3. The attempt at a solution Fn = 19*9.8cos30 = 161N Vf2 = Vi2 + 2ad 0 = 202 + 2a(60) -400 = 120a a = -3.33 m/s2 F = ma F = 19 * -3.33 = 63.27N Ff = [tex]\mu[/tex]mgcosx 63.27 = [tex]\mu[/tex]19*9.8*cos30 [tex]\mu[/tex] = .393 Is this correct? Is the parallel component required in this case? In what cases is it required?