1K20.30 Static vs. Sliding Friction (No Computer)


Kinetic and static friction


Show that static friction is greater than kinetic friction by pulling on a wooden box using a spring scale.



  • [1] Wooden box with metal slipper
  • [1] Steel brick
  • [1] 40 N spring scale
  • [1] Wooden board
  • [2] C-clamp

Classroom Assembly

  1. Clamp the board to a table.

Important Notes

  • The steel brick is a bit heavy. Handle with care.


  1. Put the box on the board.
  2. Put the brick in the box.
  3. Pull on the box with the 40 N scale, careful to let students see the reading. Slowly increase the force until the box starts moving, then decrease the pulling force so that the box moves at constant velocity.


Additional Resources


  • PIRA 1K20.35


  • Don't attempt this at home!

Last revised

  • 2020


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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.