Featured in PASCO’s Advanced Physics Teacher Guide

Advanced Physics Teacher Guide


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

Harmonic Motion & Pendulums

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


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

Photogate Pendulum Set


Set of four pendula (brass, plastic, wood, and aluminum) that are ideal for PASCO’s Photogate Head and Photogate Accessory in timing experiments.

Photogate Head


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


The Large Base and Support Rod includes built-in leveling screws and an aluminum rod that is 12.7 mm (1/2 in.) in diameter and 45 cm long.

Pendulum Clamp


Hang up to three pendula from precisely the same height.

Materials Used:

Meter Stick
Pendulum Bob

The Associated Bundle:

Advanced Physics Standard Sensor Bundle


This bundle contains the probeware needed to perform all 37 lab activities in the Advanced Physics lab manual.

Interface Required

This experiment may require software and an interface for data collection.