Waterwheel Work: Energy Transformations and Rotational Rates
Students learn the history of the waterwheel and common uses for water turbines today. They explore kinetic energy by creating their own experimental waterwheel from a two-liter plastic bottle. They investigate the transformations of energy involved in turning the blades of a hydro-turbine into work, and experiment with how weight affects the rotational rate of the waterwheel. Students also discuss and explore the characteristics of hydroelectric plants.
Students hold the plastic bottle waterwheel they made.
Throughout human history, waterwheels performed many types of mechanical work: saw timber, drive pumps, run farm equipment, trip hammers, grind grains into flour, make iron products and power textile mills. Today, the modern equivalents of waterwheels are the huge turbines of hydroelectric power plants, which generate electricity that we use everyday to perform all types of work: heating, cooling, refrigeration, and the powering of appliances, televisions and entertainment. Hydropower is a way to produce electricity using a renewable energy source that does not use fossil fuels, pollute or produce greenhouse gases. Yet, such big projects require engineers to consider all the implications of their impact on the surrounding environment.
After this activity, students should be able to:
- Describe hydropower as a source of renewable energy.
- Discuss the history and uses for a waterwheel.
- Explain how engineers design and redesign hydropower technologies.
- Use counting to measure the rate of revolution of a waterwheel.