The Underdamped Pendulum

The underdamped pendulum presents an interesting case of dynamics. When provided sufficient torque of T > m g l it will begin doing full revolutions around the center. Because the amount of friction is insufficient to stop it immediately, an amount of torque T < m g l will keep the pendulum undergoing the same basic behavior, though at a reduced speed. This video shows a pendulum on the top and the torque applied as a function of time in the bottom. Units of the x-axis are normalized time -- units of 2*pi*sqrt(l/g). Units on the y-axis are units of torque -- normalized by m g l.