1. The problem statement, all variables and given/known data The device shown in the figure below (Figure 1) is one version of a Russell traction apparatus. It has two functions: to support the injured leg horizontally and at the same time provide a horizontal traction force on it. This can be done by adjusting the weight W and the angle θ. For this patient, his leg (including his foot) is 81.0 cm long (measured from the hip joint) and has a mass of 16.6 kg . Its center of mass is 41.0 cm from the hip joint. A support strap is attached to the patient's ankle 13.0 cm from the bottom of his foot. What weight W(in N) is needed to support the leg horizontally? Massleg=16.6kg Radiusleg=81.0cm or .810m Radiuscm=41.0cm or .410m Radiuspulley=13.0cm from foot or 68.0cm from pivot=.680m 2. Relevant equations Στ(torque) = 0 τ= T⋅R F=ma 3. The attempt at a solution Force of the center mass is equal to the mass times the acceleration(downward). Fcm = m * a = 16.6kg ⋅ -9.8m/s2 Fcm = -162.68N Fcm * Rcm = -162.68N * .410m = -66.988 N*m = τ Now, I sum the torques and solve for Fpulley Fpulley * Rpulley - Fcm * Rcm = 0 Fpulley*.68m = -66.988N*m Fpulley = -98.08647N = -98.1N I have tried inputing -98.1 and 98.1, both were wrong. Any suggestions? I've looked elsewhere online and this is pretty much the template they provide so maybe I'm getting my numbers wrong somewhere?