Simple Harmonic Motion and Pendulums

Featured in PASCO’s Advanced Physics Teacher Guide

Advanced Physics Teacher Guide (PS-2879C)

This manual features over 30 College Board curriculum and AP Physics exam inspired lab activities.

Lab Summary

Use a photogate and pendulum to determine earth's gravitational acceleration.


Using a simple pendulum, design and conduct an experiment to determine earth's gravitational acceleration through a graphical method.

  • Explore the basic mathematical concept and behavior of a simple pendulum.
  • Using the theory and mathematical relationships involving a simple pendulum, determine an experimental value for earth's gravitational acceleration.


Students gain experience conducting the following procedures:

  • Measuring the pendulum arm length and period for several different pendulum arm lengths while holding the bob mass constant.
  • Plotting pendulum period versus square root of arm length to create a linear relationship.
  • Using a line of best fit whose slope is equal to 2π/√g to extrapolate a value for the acceleration due to gravity.

Sensors / Equipment Used

PASPORT Digital Adapter (PS-2159)

The Digital Adapter allows ScienceWorkshop analog sensors to be connected and used with PASPORT interfaces.

Photogate Pendulum Set (ME-8752)

Set of four pendula (brass, plastic, wood, and aluminum) that are ideal for timing experiments with photogates.

Photogate Head (ME-9498A)

Monitors the motion of objects passing through its gate, counting events as the object breaks the infrared beam. For use with PASPORT and ScienceWorkshop Interfaces.

Base and Support Rod (ME-9355)

Provides a level base for basic lab experiments.

Pendulum Clamp (ME-9506)

Hang up to three pendula from precisely the same height.

Materials Used

Meter Stick
Pendulum Bob

The Associated Bundle