This is a demonstration of how torques create rotations. Up to four different masses can be placed on a lever ("See-Saw") and the rotation of the lever observed. The positions and values of the masses can be changed, as can the fulcrum point of the lever. The initial torque on the system is calculated and displayed.
This material is now for-fee. See note below.
To develop an understanding of the properties of torque.
Target Student Population:
High school or introductory college physics students. This applet can also be used by younger students for quantitative studies.
Prerequisite Knowledge or Skills:
Type of Material:
Online lab or tutorial with some directions.
Requires a browser with the Shockwave plug-in installed.
Evaluation and Observation
This applet lets students investigate the concepts of torque and moment arm. The ability to place from one to four masses on the lever at any position, and move the fulcrum, makes possible a wide range of investigations.
The rate of rotation of the lever depends on the torque.
This is a simulation of a relatively simple physical experiment that might be more immediate and compelling for students.
In cases where all the mass is on one side of the fulcrum, the simulated rate of rotation of the lever is not accurate, with very fast rotations occuring for smaller torques.
Potential Effectiveness as a Teaching Tool
Torque is a very difficult concept for students to understand. Investigations, or play, with this applet will help students understand that both force and distance from the fulcrum influence the torque.
This applet can be used for conceptual understanding and student-centered discovery exercises.
The physics of torque and rotation are not described in this applet. This information must be provided by some other source, such as the instructor or textbook.
Ease of Use for Both Students and Faculty
This applet is very simple to use and intuitive. There are simple instructions available for running the simulation.
The ability to copy an image of the applet to the clipboard and paste it into another application is a significant benefit.
Other Issues and Comments:
Since this review was written, the access to this material has changed to a for-fee subscription. Although the MERLOT/Physics Editorial Board do not generally review for-fee materials, this review will remain posted for our users.