The Car with a Lot of Potential
Student thinking about gears in motionCopyright flickr.com 2014. CC BY-SA 2.0 https://www.flickr.com/photos/sanjoselibrary/14308844895
Working in teams of three, students perform quantitative observational experiments on the motion of LEGO® MINDSTORMS® robotic vehicles powered by the stored potential energy of rubber bands. They experiment with different vehicle modifications (such as wheel type, payload, rubber band type and lubrication) and monitor the effects on vehicle performance. The main point of the activity, however, is for students to understand that through the manipulation of mechanics, a rubber band can be used in a rather non-traditional configuration to power a vehicle. In addition, this activity reinforces the idea that elastic energy can be stored as potential energy.
Mechanical engineering applications—such as wind turbines, electric stoves and television screens—typically require the manipulation and transference of energy. This activity provides students with an example of the application of the elastic energy of a rubber band to a non-ideal mechanical setup, mimicking real-world challenges to design efficient engines with aerodynamic designs. Students test designs and tabulate observations based on varied experimental parameters.
After this activity, students should be able to:
- Test the effects of altering the number of turns of a rubber band on the motion of a model vehicle, reinforced with quantitative results.
- Test the effectiveness of varying one or more of the following on vehicle motion: wheel type, payload weight, rubber band type and lubrication.
- Report on the conclusions and collaborate with other groups to optimize vehicle parameters.