A heavy weight is fixed on one end of a string and the other end of the string is suspended on a stand to form a pendulum. The system is an closed one (energy neither enters nor leaves). The total energy of each system remains constant, but it is continually changing forms. It is shared between potential energy (gravitational) and kinetic energy of motion.
|small rod and clamp||Above 021-23|
|ring stand||Ring stand in SW 017|