Playlist: Energy
Talking about energy is tricky because everyday words can also have specialized scientific meanings. Through the process of defining key terms like “power,” “work,” and even “energy” itself, this program uses a roller coaster, a harmless train wreck, ice-skaters, a boulder, a human cannonball, night-vision goggles, and a supernova to introduce students to kinetic and potential energy, electrical energy, chemical energy, nuclear energy, and conduction, convection, and radiation of heat. A viewable/printable instructor’s guide is available online. A Films for the Humanities & Sciences Production. A part of the series Physics in Action. (33 minutes)
Energy is the capacity to do work, and work is the transfer of energy. Energy manifests itself as kinetic or potential energy, and heat. The action of a roller coaster illustrates these concepts.
Kinetic energy equals 1/2 mass x velocity squared. In physics, force is what moves something over a distance. Units of force are called Newtons. "Newton-meters" show how force is related to energy.
Potential energy is the mechanical energy an object has stored from having had work done on it. Gravity=9.8 m/s2; work = mad; physical energy = mgh.
The Second Law of Thermodynamics: Randomness in the universe always increases. Heat is due to random movement of many molecules. Heat is transferred by conduction, convection, or radiation.
Electrical energy is work being done by charged particles at the atomic scale. Vocabulary includes potential difference, volts, joules, coulombs, and electron volt.
Chemical energy is due to changes in electrical potential energy at the atomic level. Vocabulary includes quanta, chemical bonding, and ground states.
E = mc2 shows how the smallest amounts of matter are converted into large amounts of energy. Vocabulary includes fusion, fission, and strong nuclear force.
Review of energy principles include human use of energy in watts and kilowatt hours (kWh). In the USA, most energy comes from burning oil and coal. Other forms of energy include solar, nuclear, wind, wave, and waste.