A thin stick of mass 400 grams is 2 meters long, and is free to pivot about a point at one end. Initially at rest, the stick is held so that it is vertical such that the "free end" is above the pivot. It is then given a tiny nudge and released. Consider the stick as it moves as a pendulum. At the instant that the stick is again vertical (with the free end below the pivot), find
a) the change of the gravitational potential energy of the stick (from its initial value)
b) the rotational kinetic energy,
c) the velocity and accelertion of the tip,
r) the velocity and accelertion of the center of mass of the stick, and
e) the force supplied at the pivot.