The ratio of the mass of the earth to the mass of the moon is 82.6. Suppose that the radius of the earth is about 6494.0 km and that the distance among the center of the earth and the moon is 387319.0 km.
a. Determine the distance of the center of mass of the earth-moon system from the center of the earth.
b. The earth-moon system moves in a circular orbit around the sun. How far from the circular orbit does the center of the earth move radically (i.e. toward or away from the sun) through the lunar month?