Compute the gravitational attraction on a unit mass at the origin due to the mass (of constant density) occupying the volume inside the sphere r = 2a and above the plane z = a. Hint: The magnitude of the gravitational force on the unit mass due to the element of mass dM at (r, θ, φ) is (G/r2)dM. You want the z component of this since the other components of the total force are zero by symmetry. Use spherical coordinates.

Compute the gravitational attraction on a unit mass at the origin due to the mass (of constant density) occupying the volume inside the sphere r = 2a and above the plane z = a. Hint: The magnitude of the gravitational force on the unit mass due to the element of mass dM at (r, θ, φ) is (G/r2)dM. You want the z component of this since the other components of the total force are zero by symmetry. Use spherical coordinates.