Education Technology

Tic, Toc: Pendulum Motion

Published on 07/02/2009

Activity Overview

In this activity, students' will use a motion detector to plot the position versus time graph for a swinging pendulum. They will determine the period of the motion and model the position data using a cosine function.

Before the Activity

  • Connect the motion detector to the DIG/SONIC port of the CBL 2™ or DIG/SONIC 1 port of the Vernier LabPro®
  • Connect the CBL 2 or LabPro to the calculator using the Unit-to-Unit cable
  • See the attached PDF file for detailed instructions for this activity
  • Print pages 247 - 252 from the attached PDF file for your class
  • During the Activity

    Distribute the pages to your class.

    Follow the Activity procedures:

  • Hang the pendulum bob from about 80 cm of string from a rigid support
  • Position the motion detector about 1 m away from the bob, pointing at the bob
  • Measure and record the distance from the bob to the motion detector; this distance must be at least 75 cm
  • Pull back the bob not more than 20 cm before releasing it
  • Measure the period of the pendulum and record it in the Data sheet
  • Swing the bob away from the motion detector and observe the distance versus time graph
  • Compare the data to the cosine model
  • Determine the period of the pendulum
  • After the Activity

    Students' will analyze data and complete the Data Collection and Analysis Sheet. They will also answer questions listed in it.

    Review student results

  • As a class, discuss questions that appeared to be more challenging
  • Re-teach concepts as necessary