1. The problem statement, all variables and given/known data Hi, I was wondering how you would isolate for and calculate the coefficient of friction in an Atwood pulley, with one fixed pulley, with two masses hanging off of it on either side. There is no table or surface that the masses are touching or resting on, they are both free-hanging on either side of the pulley. There is no person applying a force to it, the pulley is free-standing. No values are given, I am just trying to make a general equation for the coefficient of friction. A general diagram of the situation is: 2. Relevant equations I know that, for m1, Fnet = Force of tension - Force of Gravity - Force of Friction, if it were to set "up" as the positive direction And for m2, Fnet = Force of Gravity - Force of tension - force of friction Force of friction = μ X Force normal Feel free to correct me if I'm wrong for any of these equations 3. The attempt at a solution Fnet1 = Ft - Fg - μFn m1a = Ft - mg - μFn In this case, would Fn be equivalent to Fg???????? m1a = Ft - mg - μmg μmg = Ft - mg - m1a μ = (Ft - mg - m1a) / mg I am attempting this entirely off of assumptions, as I am not aware of the actual friction forces or formulas on the pulley. Thanks for the help, it is greatly appreciated!