Learners investigate energy conversions as they redesign a coal-burning electrical generating station.
After completing this tutorial, you will be able to complete the following:
Energy can be described as the potential or ability to move objects or cause a change in matter. The SI unit for energy is the joule (J), named for James Joule, who showed that work can be converted to heat. The joule is the work done by a force of one newton (N) acting through a distance of one meter. Examples of types of energy include chemical, electrical, heat (thermal), kinetic, light, nuclear, potential, thermal, solar, sound, and wind. Three types of potential energy are elastic, chemical, and gravitational. The total amount of potential and kinetic energy in a system is called mechanical energy.
The first law of thermodynamics or the law of conservation of energy states that energy cannot be created or destroyed. Energy simply transforms from one form to another. Even if energy seems to disappear, it does not. If, for example, a skateboard rider is coasting on a flat road, he will eventually come to a stop. It may seem that the mechanical (kinetic and potential) energy of the rider has been destroyed, but that would violate the law of conservation of energy. Instead, friction and air resistance cause some of the mechanical energy to convert to thermal energy. As the wheels roll along the pavement, the temperature of the ball bearings inside the wheels and the temperature of the surface of the wheels increase slightly. The total amount of energy stays the same as mechanical energy is transformed to thermal energy. On a large scale, the law of conservation of energy indicates that the amount of energy in the universe remains constant.
We witness the law of conservation of energy in power plants, as one form of energy is converted to another. Energy sources and power plants are the topic of much debate lately. Turn on the news any evening to hear about the price of gasoline, the merits of excavating and refining more fossil fuels domestically, safety concerns for nuclear energy at home and abroad, and where to build facilities for renewable energy. The cost and environmental impact of all of these concerns must be weighed, of course, against our economic and national security interests. Academia, business, and government play an increasingly vital role in developing technologies that increase safety and efficiency while decreasing cost, dependence on foreign nations, and environmental impact.
|Approximate Time||30 Minutes|
|Pre-requisite Concepts||conservation of energy, energy|
|Type of Tutorial||Concept Development|
|Key Vocabulary||boiler, chemical energy, coal|