Around 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 opposite side. sincosky’s mass was 79 kg. (after suspending himself, sincosky chinned himself on the rafter and then moved hand-over-hand along the rafter for about 6 feet.) if the coefficient of static friction between henry’s fingers and rafter was 0.70, what was the least magnitude of the normal force on the rafter from each thumb or opposing fingers to suspend henry via friction forces?