Calculate the acceleration of gravity as a function of depth in the earth (assume it is a sphere). You may use an average density from the attached density profile for a spherical shell (which does not have to be very thin, for example, a shell from the inner core-outer core boundary to the middle depth of the outer core). Do not make the shell contains a large density contrast. Calculate enough points to make the g profile. Note that only the mass at radius less than r contributes to the gravitational acceleration. (15 points)