Exploring Gears

Introduce students to simple and compound gear trains and how gear trains affect speed and torque using this engaging and interactive exploration activity.

Depending on the length of a class period and student prior knowledge, this lesson can be implemented across 2-5 class periods.

This file includes 10 student pages, detailed student instructions with images, data tables for recording data and observations, carefully constructed and sequenced analysis questions for students, a quick reference guide for using Gear Generator, a Teacher Guide, and Answer Key. The teacher guide includes ideas for introductory activities prior to implementing the lesson and follow up activities for after the lesson.

Exploring Gears allows students to virtually build and test gear trains using the Gear Generator simulator, a free online resource created by Abel Vincze.

In the first part of this activity, students will…

• Virtually build simple gear trains.
• Record the number of gear rotations of two meshed gears.
• Use ratios to express gear rotations.
• Record the number of teeth on two meshed gears.
• Use ratios to express tooth relationship.
• Derive the formula for determining gear ratios between two meshed gears.
• Record the Input and Output speeds of two meshed gears in rotations per minute (RPMs).
• Explore the effects of increasing and decreasing gear ratios on output speed.

In the second part of this activity, students will…
• Virtually build compound gear trains.
• Understand that compound gear trains apply the use of Driver to driven gear pairs, where gears share the same axle.
• Use fractions to represent gear ratios.
• Multiply fractions to determine compound gear ratios
• Record the Input and Output speeds of compound gear trains in rotations per minute (RPMs).
• Explore the effects of increasing and decreasing gear ratios on output speed.
• Develop an equation to determine output speed