Sand Pendulum

This apparatus is designed to demonstrate
the oscillation and movement of the pendulum. The sand pendulum is suspended from the top by two ropes and has a sand reservoir
at the end. The two ropes hanging from the top allow movement in three dimensions
. The sand filled in the sand hopper
creates a pattern below when the pendulum is released
and repeats the same pattern
when the pendulum passes through the same points. Figures and many different patterns
are obtained on the bottom table.