PIRA Classification: 1N30.56
Description: A wood block is placed at the bottom of a pendulum's trajetory. The pendulum bob itself consists of either a dead or alive ball (see 1R40.30). The dead ball displays inelastic collisions while the alive ball displays elastic collisions. When the dead ball hits the block, not much happens. When the alive ball hits the block, the block is knocked over.
Special Instructions: Hold the pendulum at a 90 degree angle and release.
Condition: OK
Setup time: 2 minutes