Question1
A neutron star has a mass of 2.0 1030 kg (about mass of our sun) and a radius of 5.4 103 m (about the height of a good-sized mountain). Assume an object falls from rest near the surface of such a star. How fast would it be moving behind it had fallen a distance of 0.016 m? (Suppose that the gravitational force is constant over the distance of the fall, and that the star is not rotating.)
Question2
The pendulum of a grandfather clock consists of a thin rod of length L (and negligible mass) attached at its upper end to a fixed point, and attached at its lower end to a point on edge of a uniform disk of radius R, mass M, and negligible thickness. The disk is free to rotate about the point of attachment. Suppose all motion is constrained to a single vertical plane near Earth's surface. Neglect friction and air resistance, as well as the rotation of earth.
What is Lagrangian for this system?