Hands-on Activity: Wide World of Gears
Educational Standards :
Pre-Req Knowledge (Return to Contents)
THe teacher should be familiar with LEGO MINDSTORMS NXT as a building and programming platform. The following Internet site provides primers for NXT building and programming.
Knowledge of pairing NXT Intelligent Bricks via Bluetooth is necessary. The following Internet sites provide instructive steps for pairing NXT bricks using Bluetooth.
Learning Objectives (Return to Contents)
After this activity, students should be able to:
Materials List (Return to Contents)
To share with the entire class:
Option 1 (less expensive option)
Option 2 (best option if your school is planning to purchase LEGO MINDSTORMS equipment in bulk; this allows two groups to operate with their own NXT bricks, configured as either the "gearing up" or "gearing down" racer)
Introduction/Motivation (Return to Contents)
(Be ready to show students some example gears.)
Today, we will do a fun activity to learn all about gears! Has anyone ever seen a gear before? Where might you find a gear? (Possible answers: Bike, clock, watch.) You may have seen a gear before but maybe weren't sure how they are used or why.
Today we are going to learn all about how gears work. Gears can be used together to rotate in succession. As one gear turns, either because my hand is moving it or because a motor is moving it, another can turn as well because it is connected, giving an arrangement of gears so that they interact with one another. (Note to teacher: It is very helpful visually to hold up two gears in front of students and demonstrate how one rotating gear can cause the second gear to rotate.)
In this activity, we'll learn two different ways gears can be connected with each other. They are termed "gear up" and "gear down." But first, let's go back to our examples. Who remembers where gears are seen in everyday life? Based on these examples, such as bikes, watches and clocks, which are all simple machines that engineers have designed, why might engineers use gears? What is their purpose? What happens when you "change gears" on a bike? (Expected answers: It makes it easier to go faster or easier to go up a hill, pedaling becomes more difficult or easier, etc.)
(At this point, introduce the simplified definitions of "gearing up" and "gearing down," defined strictly by the arrangement of gears.) Let's investigate as a class how each set-up, gearing up and gearing down, affects the speed and the strength of the different cars.
(After conclusions are drawn from the observations of the experiments, present more generalized definitions of "gearing up" and "gearing down," as provided in the Vocabulary section.)
Vocabulary/Definitions (Return to Contents)
Procedure (Return to Contents)
Before the Activity
With the Students
Attachments (Return to Contents)
Assessment (Return to Contents)
Pre-Assessment Quiz: Distribute the Gears Pre-Assessment Survey, consisting of questions designed to probe students' current understanding of the application of gears.
Discussion: After students have completed their observations on both configurations, hold a class discussion and guide class' conclusion of the hypothesis and tabulate average speeds (across all trials) for each of the racers. Follow with racing competitions.
Post-Assessment Quiz: Distribute the Gears Post-Assessment Survey to students to evaluate what they learned about gears during the activity.
Supporting Program (Return to Contents)Applying Mechatronics to Promote Science (AMPS) GK-12 Program, Polytechnic Institute of New York University
Acknowledgements (Return to Contents)
The development of this activity was supported by the Applying Mechatronics to Promote Science (AMPS) Program funded by National Science Foundation GK-12 grant no. 0741714. However, these contents do not necessarily represent the policies of the NSF and you should not assume endorsement by the federal government