1. The problem statement, all variables and given/known data In about 1915, Henry Sincosky of Philadelphia suspended himself from a rafter by gripping the rafter with the thumb of each hand on one side and the fingers on the other side (Fig. 6-22). Sincosky's mass was 82.0 kg. If the coefficient of static friction between hand and rafter was 0.700, what was the least magnitude of the normal force on the rafter from each thumb or opposite fingers? http://edugen.wiley.com/edugen/courses/crs1650/art/qb/qu/c06/pict_6_22.gif 2. Relevant equations Fnet = Ma Fs,max = UsFn Us = Coefficient of static friction 3. The attempt at a solution With Normal force and Gravitational force pointing down and Static Friction pointing up on the free-body diagram, I for Fs - Fn - Fg = 0 [Zero acceleration]. Then I put Fg = Fs - Fn and substituted Fs with UsFn. Got the answer 2680 [rounded to 3 sig figs] but was the incorrect answer. I have a feeling that it's my free body diagram that's wrong.