Bowling Ball Pendulum

This demo is meant to showcase the conservation law of energy as well as the conversion of gravitational potential energy into kinetic energy. The main physical point is that the bowling ball will not return to a higher point from where it was released as long as no additional energy is added to the system (it will not hurt the willing volunteer).

  • Pre-Show Checks:
    • Ensure there are no obstructions in the bowling ball’s path
    • Ensure the bowling ball is firmly secured in a readily accessible place
    • Ensure the wire does not obstruct the pathway around the table for anyone else
    • Ensure the stool is appropriately placed
  • Demo Checks:
    • Ask for a volunteer and fill in time while they make their way to the stage
    • Ask for their name and exchange some light banter
    • Direct them to the stool
    • Briefly explain the concept of a pendulum and mention the weight of the ball
    • Add in some jokes or banter before having the volunteer drop the bowling ball
    • Dropping the ball (and not in the bad way):
      • Ask the volunteer to hold the ball as close as possible to their face
      • Advise them to let go of the ball and not to push it at your signal
      • Warn them not to move forward or move their arms
      • Let the ball swing back and forth a couple times
      • Thank the volunteer and dismiss them
    • Explain the concept of the conservation of energy (neither created nor destroyed) and connect it to the exchange between potential and kinetic energy (PE1 + KE1 = PE2 + KE2)
      • Use this as a means of explaining that the bowling ball would not reach a point higher from where it was released and that the volunteer was in no danger

Braden Buck, 2022-23 Wonders of Physics Outreach Fellow