3A40.22 Balls and Bowl


Simple harmonic motion


The motion of a ball placed in a bowl is an example of simple harmonic motion. When the ball is placed at the centre of the bowl, the net force acting on the ball is zero and thus there is no motion. Now if the ball is released from a position near the edge of the bowl, the ball moves back and forth about a mean position until all of its energy is lost due to friction.



  • [1] Clear bowl
  • [2] Rubber ball
  • [1] Container of clear and orange beads

Important Notes

  • Keep the small beads in the provided container after using it.


  1. Place the rubber ball at the centre of the bowl and show that the ball remains stationary.
  2. Release the ball from the edge of the bowl and point out that the ball undergoes oscillatory motion.
  3. Repeat step 1 to 2 using small beads.


Additional Resources


  • PIRA 3A40.22


  • Don't attempt this at home!

Last revised

  • 2018


Related AV

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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.