we have a 180-n, 5.0-m ladder leaning up against a frictionless glass wall. the ladder makes a 53.1 degree angle with the ground, which does have friction. dr. harbison (who weighs 800 n) climbs 3/4 of the way up the ladder to clean the gutters. what coefficient of static friction is needed between the ground and the ladder such that the ladder does not slip?
