*69. Figure 5.57 shows a spherical ball hanging on a string on a smooth, frictionless wall. The mass of the ball is m, its radius is R, and the length of the string is 7. Draw a "free-body" diagram with all the forces acting on the ball. Find the normal force between the ball and the wall. Show that N→ 0 as → ∞o. 1 R FIGURE 5.57 Ball on string against wall.