calculate the rotational kinetic energy of each sphere.

For the spheres in the previous problem, assume rotation along
an axis that passes through the center and calculate the rotational kinetic energy of each
sphere. If both spheres are rolled down an inclined plane, which one will reach the end of
the plane first? Hint : You can calculate the Lagrangian for each sphere and then obtain
their accelerations.

(the previous problem: Two spheres have the same diameter and mass, but one is solid
and the other one is hollow. Assuming homogeneous densities and putting the origin at the
center, calculate the inertia tensor of each sphere.)