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Great Neck South Middle School Technology Energy and Electricity Introduction. What is energy?.
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Great Neck South Middle SchoolTechnologyEnergy and Electricity Introduction
What is energy? • Energy is the ability to do work, or cause change. Energy is literally what makes the world and everything in it go. Energy is the magic stuff stored in the battery that makes the flashlight work. The gasoline in a car’s gas tank contains energy. The car’s engine merely converts the gasoline’s energy into a usable form.
While there are many forms and sources of energy, there are only two types: Potential Kinetic
Kinetic • “energy associated with motion.” • When discussing kinetic energy, it’s important to keep in mind that the mass andvelocity of an object determine its kinetic energy. We can take a look at kinetic energy by throwing a basketball and a baseball.
Potential “The energy something has which is stored and not moving.” • “the energy that a piece of matter has because of its position or because of the arrangement of parts” because the matter has the potential, or opportunity, to do work. • There are two types of potential energy: elastic potential energy and gravitational potential energy. • Water behind a dam has gravitational potential energy. • A stretched rubber band has elastic potential
Forms of energy • Mechanical — the energy of motion • Electrical — think lightning or electricity moving through electrical wires • Electromagnetic or radiant — energy of magnetism and light • Chemical — energy produced by chemical reactions like those that occur in batteries • Nuclear — potential energy stored in the nuclei of atoms • Sound — the energy of vibratingsound waves • Heat – from burning fuel or the earth
Energy Conversion • Many of the devices we use every day convert energy from one form to another. • These devices are called transducers.
Transducers • Flashlight — converts chemical energy (stored in the battery) to electrical energy to light the bulb. The bulb converts the electrical energy to electromagnetic or radiant energy.
Transducers • Toaster — converts electrical energy into thermal energy. • Car engine — converts the chemical energy stored in the gasoline into mechanical and thermal energy.
What do transducers do? • Convert one energy type to another.
How do we produce electricity? • Generators - - - - > Mechanical • Batteries - - - - - > Chemicals • Photovoltaic Cells - > Light • Piezio electric - - > Pressure
Generator – A mechanical device that produces electricity by a process of rotating a magnet inside a coil of copper wire. A generator is a transducer that uses rotary mechanical motion to produces electricity.
Natural Energy All Renewable Non Consumed when used Solar Wind Water Geothermal
Energy Existing in Nature Natural energy sources are ALL RENEWABLE
Wind Farm Middlegruden
Heat Energy • Geothermal – heat from the earth • Solar Thermal – heat from the sun
Solar Energy Light Heat
Solar Energy Light energy -- Electrical energy Uses Photovoltaic Cell
Water Energy • Water must be Moving • Hydroelectric Power- dams & rivers • Tidal – vertical movement of tides • Wave – using the up/down motion of waves • Thermal-using the temperature difference of oceans
Oregon State Wave Park A 2.25-megawatt project off the coast of Portugal went on line this fall (2008), becoming the world's first commercial wave-energy development in operation. It can supply 1,500 households with electricity.
Fuels • Advantages • Portable • Storable • Disadvantages • Pollute
Energy from Fuels • Must Be Burned to Create Steam • Pollute • Some are : • Renewable • Non Renewable
Renewable Fuels Replaceable in a short period of time • Biomass - - - - -> Once alive • Plants • Trees-Wood • Corn, Sugar Cane –Ethanol Alcohol • Algae • Garbage
Non Renewable Fuels • Fossil Fuels • Petroleum- Oil • Gasoline • Heating Oil • Plastics • Coal • Natural Gas
Non Renewable Energy • Nuclear • Fission - split atoms • Fusion – combine atoms
Energy Conservation • Shut off lights • Fluorescent/Compact lights