1N30.60 Dropping Superballs (Ninja Balls)


Momentum and energy transfer through inelastic collisions


When the collision balls are dropped, the top ball (the only unconstrained ball) flies off with greatly increased energy and momentum.



  • [1] Set of collision balls

Important Notes

  • The top ball is small and hard to find. Pay attention to where it lands.


  1. Ensure the top ball is on the rod in line with the other collision balls.
  2. From a height of about 30 cm, drop the collision balls onto a table with the largest ball at the bottom. The smallest top ball will fly off with greatly increased energy and momentum.


Additional Resources


  • PIRA 1N30.60


  • Don't attempt this at home!

Last revised

  • 2018


  • Original construction: purchased.

Related AV

Related demos

  • Double ball drop


If you have any questions about the demos or notes you would like to add to this page, contact Ricky Chu at ricky_chu AT sfu DOT ca.