3A20.40 Harmonic Oscillator Cart


Simple harmonic motion, energy


A wheeled cart with springs attached oscillates on a track. A motion detector connected to a computer helps graph the cart's motion.



  • [1] Cart with motion detector plate
  • [1] Track
  • [2] Spring
  • [1] Motion detector with post attached
  • [1] USB A-B cable
  • [1] Lab stand
  • [1] 90-degree clamp
  • [1] Computer with Logger Pro (Windows or Mac OS)

Classroom Assembly

  1. Start up the computer.
  2. Attach the cart to the plate.
  3. Hook the springs to the cart and the track.
  4. Mount the motion detector to the lab stand and position it to view straight down the track at the plate on the cart.
  5. Connect the computer to the motion detector using the USB cable.
  6. Zero the motion detector at the cart's equilibrium position.
  7. Start Logger Pro and make sure that the detector captures the cart's full range of mottion.

Important Notes

  • Knowledge of Logger Pro is essential.
  • If the graph of cart motion clips at the high or low ends, try raising the motion detector or removing objects near the track.


  1. Start the cart oscillations.
  2. Start the data collection.
  3. Go to a different page in the Logger Pro file for other measurements.


Additional Resources


  • PIRA 3A20.40


  • Don't attempt this at home!

Last revised

  • 2019


  • If running the computer, on the day before, check that all Windows updates have been applied.

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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.