1J40.41 Loaded Beam


Static torque


A metal rod is suspended by two spring scales located at equal distances from its ends. A mass is hung at known positions along the rod to explore different weight distributions and static torques.



  • [1] Metal rod
  • [2] Spring scale
  • [1] Mass
  • [1] Hook
  • [2] Lab stand
  • [2] 90-degree clamp
  • [1] Metre stick

Classroom Assembly

  1. Hang each spring scale to a lab stand.
  2. Zero the spring scales and attach one to each metal rod.
  3. Adjust the height of the scales so that the rod is horizontal.


  1. Start by hanging the mass at the middle of the rod. The scales should read the same value.
  2. Slide the mass to the left and/or to the right.

Additional Resources


  • PIRA 1J40.41


  • Don't attempt this at home!

Last revised

  • 2017


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.