75. A plumb bob (a mass m hanging on a string) is deflected from the vertical by an angle 0 due to a massive mountain nearby (Fig. 5-44). (a) Find an approximate formula for 0 in terms of the mass of the mountain, my, the distance to its center, DM, and the radius and mass of the Earth. (b) Make a rough estimate of the mass of Mt. Everest, assuming it has the shape of a cone 4000m high and base of diameter 4000 m. Assume its mass per unit volume is 3000 kg per m'. (c) Estimate the angle o of the plumb bob if it is 5 km from the center of Mt. Everest. DM FM FIGURE 5-44 Problem 75