Question

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 (see the figure). Sincosky's mass was 87.6 kg. If the coefficient of static friction between hand and rafter was 0.743, what was the least magnitude of the normal force on the rafter from each thumb or opposite fingers?

I thought that k*normal >= weight, where k is the coefficient of friction so the normal would equal (87.6*9.8)/0.743

Answer 1

Nevermind, the problem was that I had to divide the resultant by 4