8. A person decides to stretch by leaning against a wall show below. The horizontal distance from the feet to the wall is 0.914m. The distance from the hands to the feet of the person is 2.1m. The center of mass of the person is a distance of 0.94m along the body of the person from the center of mass to the feet. There is negligible friction between the hands and the wall. If the person's feet are just on the verge of sliding on the floor, what is the coefficient of friction between the feet and the ground? Center of mass