Chapter 3 Section 2: Energy Can change forms but is never lost. Review Energy is the ability to do work or to cause a change. Kinetic and Potential Energy are the main types There are several types of Energy, such as Nuclear, Mechanical, Thermal, Electromagnetic, Sound, and Chemical. Energy Energy often needs to be transformed in order to produce a useful form of energy. Conservation of Energy The law of conservation of energy states that energy is never created or destroyed. No matter how energy is transferred or transformed, it continues to exist in one form or another. Energy Energy can be transformed in many different ways, including from PE to KE and back again. Energy Efficiency A measurement of usable energy after an energy conversion; the ratio of usable energy to the total energy after an energy conversion Energy Efficiency ENERGY STAR bulbs use 75 percent less energy than standard incandescent bulbs and last up to 10 times longer Produces 75 percent less heat, so they're safer to operate and cuts energy costs associated with home cooling. Unwanted forms of Energy When energy changes forms, the total amount of energy does not change, but some of the energy may convert to unusable or unwanted forms. Usually the unwanted form is Heat Kinetic vs Potential The picture on the left, because the child is at a higher point above the ground. Sun is the indirect source for almost all of Earth’s energy, including plants, making sugars, as well as fossil fuels that are burned for electrical energy or heat. a law that states that energy can never be created or destroyed applies to the whole universe energy simply changes form The kinetic energy has been changed into sound, heat, and then into kinetic energy in the second ball Energy efficiency is a measure of usable energy after an energy conversion. Energy-efficient appliances convert a greater percentage of energy into the desired form.
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