a 5.00-m-long ladder, weighing 200 n, rests against a smooth vertical wall with its base on a horizontal rough floor, a distance of 1.20 m away from the wall. the center of mass of the ladder is 2.50 m from its base, and the coefficient of static friction between the ladder and the floor is 0.200. how far up the ladder, measured along the ladder, can a 600-n person climb before the ladder begins to slip?