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What is energy? • Energy is the Ability To Do Work • Energy does things for us. – It moves cars along the road and boats over the water. – It bakes a cake in the oven and keeps ice frozen in the freezer. – It plays our favorite songs on the radio and lights our homes. – It makes our bodies grow and allows our minds to think. – People have learned how to change energy from one form to another so that we can do work more easily and live more comfortably. – Energy comes in different forms: • Heat (thermal) • Light (radiant) • Mechanical • Electrical • Chemical • Nuclear energy Ways that energy is converted into new forms of energy Energy is in everything • We use energy to do everything we do, from making a jump shot to baking our favorite cookies to sending astronauts into space -energy is there, making sure we have the power to do it all. • There are two types of energy -- stored (potential) energy and working (kinetic) energy. – For example, the food you eat contains chemical energy, and your body stores this energy until you release it when you work or play. KINETIC ENERGY • Kinetic energy is motion––of waves, electrons, atoms, molecules, substances, and objects. • Some forms of kinetic energy are: – – – – – Electrical Energy Radiant Energy Thermal Energy Motion Energy Sound POTENTIAL ENERGY • Potential energy is stored energy and the energy of position––gravitational energy. • There are several forms of potential energy. – – – – Chemical Energy Stored Mechanical Energy Nuclear Energy Gravitational Energy Key Vocabulary Energy – the ability to cause changes in matter Kinetic Energy – The energy of motion, or energy in use. Potential Energy – The energy an object has because of its place or its condition. Transformation – The transfer of energy back and forth between kinetic and potential energy. Types of Energy Electrical Energy • Electrical Energy is when motion, light or heat is produced by an electrical current like the electric coils on your stove. • Electrical charges moving through a wire is called electricity. Lightning is another example of electrical energy. Radiant Energy (light) • is energy that travels in transverse waves. Radiant energy includes visible light, x-rays, gamma rays and radio waves. Light is one type of radiant energy. Solar energy is an example of radiant energy. Heat Energy • Heat energy is where motion or a rise in temperature is caused by heat like a fire in your fireplace • We use heat for a lot of things, like warming our homes and cooking our food. • Heat energy moves in three ways: 1. Conduction 2. Convection 3. Radiation Mechanical Energy Mechanical Energy is the energy of motion that does the work like when wind turns a windmill. Chemical Energy Chemical Energy is the chemical reaction causing changes; food and fuel both store chemical energy. Sound Energy Sound Energy is the movement of energy through substances in longitudinal (compression/rarefaction) waves. Sound is produced when a force causes an object or substance to vibrate––the energy is transferred through the substance in a wave. Gravitational Energy Gravitational Energy - where motion, like water going over a dam, is caused by gravity's pull. Key Vocabulary Solar energy – The energy of sunlight. Light energy – The movement of energy that travels in waves. Electrical energy – The movement of energy through an electrical current. Heat energy – The transfer of thermal energy from one thing to another. Mechanical energy – The energy of motion. Chemical energy – Energy from a chemical reaction. Sound energy – The movement of energy through vibrations. Sources of Energy Oil and Gas • Oil and Gas are used to produce electrical energy, mechanical energy, and heat energy. • Oil and gas are pumped from wells deep in the ground and under the ocean. They are then sent through pipelines to be refined or cleaned. Wood and Coal • Wood and Coal are used to produce mechanical, electrical and heat energy. Coal is mined underground near the earth's surface. It is burned in its natural form to produce heat. Coal can also be converted to a liquid or gas form. Water Power (hydropower) • Water Power can produce mechanical and electrical energy. Dams are used to contain flowing river water forming lakes and reservoirs. As water flows downhill it is channeled to a turbine or water wheel. The force of the flowing water turns the turbine or wheel, which turns a generator to make the electricity. Water power has been used for hundreds of years to create mechanical energy for grinding, pumping and running machinery Sun Power (solar energy) • Sun Power gives us heat and light energy. The sun makes energy from nuclear fusion. Billions of times each second, hydrogen atoms collide with each other and produce helium. Every second 4.7 million tons of hydrogen become energy Nuclear Power • Nuclear Power is used to make electricity. Inside a reactor atoms from a fuel called uranium are split by neutrons (nuclear fission). This energy is released as heat which changes water into steam that turns turbine generators. Wind Power • Wind Power is used for mechanical and electrical energy. Wind has been used for hundreds of years to help ships sail and turn windmills to pump water for irrigation. Geothermal Power • Geothermal is heat energy from deep in the earth using special pipes buried underground. In some areas of the world steam is collected and used to turn turbine generators. Conservation of energy The law of conservation of energy says that energy is neither created nor destroyed. When we use energy, it doesn’t disappear. We change it from one form of energy into another.