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# Energy

## on May 03, 2012

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## EnergyPresentation Transcript

• energy ● Energy is the ability to do work. ● Both living and non-living systems need to function. FORMS OF ENERGYPotential Kinetic Light Heat Electrical Sound energy energy energy energy energy energy
• Potential energyPotential energy is the energy that is stored in a body as a result of its position/condition. There are 4 different forms of potential energy: (a) gravitational potential energy (b) elastic potential energy (c) chemical energy (d) nuclear energy
• Gravitational Potential Energy Gravitational potential energy is the energy that is stored in a body as a result of its elevated position. When a wreck ball is raised above the ground, it stores energy due to its elevated (raised) position in the air.
• (a) Same Height, Different MassThe greater the mass of an object and its height from the ground, the greater the gravitational potential energyHigher gravitational Lower gravitational potential energy potential energy If both of the trees are at the same height, a coconut has higher gravitational potential energy compared to an apple because the mass is greater.
• (b) Same Mass, Different Height Higher gravitational potential energy An apple of the same mass falling from a high- rise building has higher gravitational potential energy compared to the lower buildings. Lower gravitational potential energy
• elastic Potential EnergyElastic potential energy is the energy that is stored in a object (an elastic object) when it is pushed or pulled. Spring is an example of elastic object. It can be pulled down when a weight is attached to it and spring back toSpring its original shape when the weight is removed.
• When an elastic object is pushed or pulled, it stores energy which can be released to do work. ❶ When the bow is stretched, the string of the bow stores some elastic potential energy. ❷ Once he releases the string, the energy stored in the string will push the arrow forward and work is done.
• Chemical EnergyChemical energy is the energy that isstored in food, fuels and electric cells,which holds the atoms and molecules of the substances together
• Oxygen Sugar Carbon Water Energy dioxide Energy is released when our food is broken down into smaller molecules.
• nuclear EnergyNuclear energy is the energy that is stored in the nucleus of an atom and is released during nuclear reactions. A lot of nuclear energy is needed to Nucleus hold the protons and neutrons together in the nucleus of an atom. Thus, large amount of energy is released during nuclear reactions.Solid Liquid Gas
• kinetic energy Kinetic energy is an energy that a body possesses due to itsmotion. All the things that are moving possess kinetic energy.
• The Effect of Mass and Speed High speed, high kinetic energy Kinetic energy depends on speed. The faster an object moves, the greater the kinetic energy. Thats why high-speed crashes are more severe and more likely to be fatal.
• Truck Car Mass: 10,000 kg Mass: 500 kg Speed: 100 km/h Speed: 100 km/h High mass, high kinetic energy If two objects are traveling at the same speed, theobject with a larger mass will have larger kinetic energy. Thus, a truck has more kinetic energy than a car
• light energyLight energy is a form of energy which enables us to see. The Sun is our main source of light. Plants trap energy in the sunlight to make food in a process called photosynthesis.
• Solar cells collects light energy from the Sun and convert it into electrical energy to operate the calculator.Solarcells
• heat energyHeat energy is a form of energy which flows from a region of higher temperature to a region of lower temperature. • When an object gains heat, its temperature increases. • When an object loses heat, its temperature falls
• ENVIRONMENT 25 oC Heat flows from the container CONTAINER (hotter) to theHEAT oC HEAT 70 surrounding (cooler)
• ENVIRONMENT 25 oC Heat flows from surrounding CONTAINER (hotter) intoHEAT oC HEAT 10 container (cooler)
• electrical energy Electrical energy is a form of energy made available bythe flow of electrical charges such as electrons and ions. Many modern devices, machines and lightings run on electrical energy
• Power point Electrical cells Power pointElectrical cells and power points are main sourcesof electrical energy. The electrical energy from the power point comes from power stations.
• sound energySound energy is a form of energy produced by vibrations which can be detected by our ears
• Types of energyRenewable Energy Non-renewable Energy● Sources that can be ● Sources that cannot be replenished in short replenished in short period of time period of time.● Example: ● Example: - solar - petroleum and gas - wind - nuclear - geothermal - hydroelectric - biomass
• Solar energy ● A form of energy that uses light from the Sun and convert it into electrical energy in order to operate the electrical appliances. ● The Sun is the main source of solar energy.
• Solar Power PlantLight energy from the Sun is converted to electrical energy in large scale to run a small town
• Solar Car Solar panel on top of the car absorbs sunlight and change the light energy to electrical energy that is to be used to operate the car or stored in the battery supply.
• Solar HeaterSolar heater absorbssunlight and heats up the cool water to provide water into the shower
• SOLAR PANEL FOR WATER HEATING Sunlight (heat energy)Cool water in Warm water outWater pipe
• Solar lamp
• Solar Solar lamp postlight
• Solar flashlightSolar calculator
• Solar mobile phone
• How does it work? Photovoltaic cellsSolar panel that use the light energy from the Sun to produce electricity.
• Energy Conversion Light (from the Sun) Electrical energy (conversion by the photovoltaic cells)
• Mechanisms of Solar Energy Production Photovoltaic cells absorbs light energy from the Sun
• Light energy frees the electrons in the photovoltaic cellsFree electrons
• Creating a flow ofelectrons
• That flow generates the electricity and light up the bulb
• Advantages of Solar Disadvantages of Solar Energy Energy• free energy from the • electricity to be stored in Sun batteries• clean because no • not produced at night pollutants produced • only for countries that receive a lot of sunlight
• wind energy ● A form of energy which uses wind to generate electricity by kinetic energy produced when the blades are turned. ● The main source of wind energy is the wind.
• The Largest Wind Farm:Roscoe Wind Farm, Texas, USA
• Offshore Wind Farm:Copenhagen, Denmark
• Wind Farm in Thailand: Koh Larn, Chonburi
• How big is thewind turbine?
• Energy Conversion Kinetic energy (the strong windBlade turns the blades the turbine) Electrical energy (converted by the generator)
• Mechanisms of Wind Energy Production Blade Wind blows and turns the turbines Turbine Generator The moving blades then moves the generator The generator converts the kinetic energy to electrical energy
• Advantages of Wind Disadvantages of Wind Energy Energy• free energy from the • wind does not blow all wind the time• clean because no • loud noise made by the pollutants produced spinning turbines• renewable resource - it cannot be used up
• Geothermal energy ● A form of energy which uses the heat from the Earth to create steam which will eventually turn the turbine and generator to create electrical energy. ● The main source of geothermal energy are the hot spring or hot rock.
• The Largest Geothermal Power Plant: Cerro Prieto Power Plant, Mexico
• Geothermal Power Plant in Thailand: Fang, Chiang Mai
• Energy Conversion TurbineHot water out Cold water in Generator Heat Kinetic energy Electrical energy(from the center (hot vapor spins (conversion by of the Earth) the turbine) generator)
• Mechanisms TurbineHot water out Cold water in Generator Cold waters are pumped Hot rocks or magma under hot rocks or heats up the water are surface of the Earth pumped up again
• Hot water Turbine out Cold water in Generator The steams turn The generator converts turbines and the kinetic energy to generators too electrical energy
• Advantages of Disadvantages of Geothermal Energy Geothermal Energy• free energy from the • only certain parts of the Earths center Earth where hot rocks• clean because no can be found pollutants produced• renewable resource - it cannot be used up
• hydroelectric energy ● A form of energy that uses the gravitational potential energy of water to spin the turbine and generator to produce electricity. ● It is built at the base of a reservoir. ● Water is the main source of this energy.
• The Largest Hydroelectric Plant: Three Gorges Dam, China
• The Largest Dam in Thailand : Bhumibol Dam, Tak
• Energy Conversion Gravitational potential energy Electrical energy Kinetic energy Gravitational Kinetic Electricalpotential energy energy energy (water coming (water spins (conversion by down the pipe) the turbines) generator)
• Mechanisms❶ Water moving fast ❸ Turns thedown the narrow pipe generator too ❷ Water turns the turbine
• Advantages of Disadvantages of Hydroelectric Energy Hydroelectric Energy• cheap because no fuel • reservoir take up large needed to run the plant spaces and it will• clean because no destroy the countryside pollutants produced • can only built in hilly• renewable resource areas with large water - water can be replaced source when it rains
• Biomass energy ● A form of energy that uses animals and plants wastes to produce methane (natural gas) which can be use to run vehicles or to burn in order to produce electricity. ● The main source of this energy is animal and plants wastes.
• The Largest Biomass Power Plant: Prenergy plant, South Wales
• (a) Dead animals & plantsWhen animals and plants rot in the absences of air, a mixture of biogas (methane) will be produced. Methane is then burn to produced heat and eventually to generate electricity.
• (b) Alcohol Ethanol, a type ofalcohol is, corn or other sugar based plantsthrough a process called fermentation.Ethanol is used as a fuelto run motor vehicles or burn it to produce heatand electricity produced when sugarcane
• (c) WastesHousehold waste suchas food waste can be burnt to produceenergy. It can also be buried and allowed the production of methane, that will eventually use as afuel to generate heat or electricity
• Energy ConversionChemical Heat Kinetic energy Electrical energy energy energy (steam turns (conversion by(wastes) (the steam) turbine) generator)
• MechanismsThe wastes The steam turns Generator converts kineticare burned the turbine energy into electrical energy
• Advantage of Biomass Disadvantage of Biomass• cheap because wastes • the gas produced from are readily available combustion of methane will cause global warming
• Fossil fulled energy CRUDE OIL NATURAL GAS Fossil fuels are rich in carbon and hydrogen. They burn in the air to produce heat and light energy. COAL
• Fossil fuels are widely used as sources of energy in transport,homes and industries.Many vehicles run on petrol and diesel, which is obtained from crude oil.
• Formation of Coal SWAMP WATER300 million years ago 100 million years agoBefore the dinosaurs, Over millions of years, Heat and pressure many giant plants the plants were buried turned the dead died in swamps under water and dirt. plants into coal
• Formation of Crude Oil OCEAN OCEAN 300 million years ago 100 million years ago Tiny sea plants and Over millions of years, Today we drill downanimals died and were the remains were buried through layers of sand, buried on the ocean deeper and deeper. The silt and rock to reach floor. Over time they enormous heat and the rock formations were covered by pressure turned them that contain oil and gaslayers of silt and sand. into oil and gas deposits
• Energy Conversion Hot steam Turbine Generator Burning coal Cool waterChemical Heat Kinetic energy Electrical energy energy energy (steam turns (conversion by (coal) (the steam) turbine) generator)
• Mechanisms Hot steam Turbine Generator Burning coal Cool water The burning The steam The turbine turns coal heats up turns the the generator tothe cold water turbine produce electricity
• Advantages of Fossil Disadvantages of Fossil Fuels Energy Fuels Energy• can produce large • nonrenewable – it will amount of energy finish after using it up.• power station can be • production of harmful build anywhere pollutants, examples carbon dioxide, carbon monoxide, nitrogen oxide and etc • the mining of fossil fuels causes damage to the environment
• Mexican Gulf Oil SpillMexican Gulf oil ring has spilled between 17 and 39 million gallons, making it the worst spill in American history.
• The National Wildlife Federation reports that already more than 150 threatened or endangered sea turtles are dead. And 316 sea birds, mostly brownpelicans and northern gannets, have been found dead.
• Honkeiko Colliery, ChinaApril 26, 1942, the worst mining disaster of all time, 1,549 miners died in a mine operated in Japanese occupied Manchuria. China has a horrible history of mine safety.
• Nuclear energyNuclear energy is made when uranium is split with accelerated neutron and a huge amount of heat energy is produced. Accelerated neutrons Lighter element Neutron + HEAT Lighter element Uranium 235 Neutron
• Chernobyl Disaster It occurred on 26 April 1986 and it is considered the worst nuclear power plant accident in history. It is estimated that 56 people died from the direct explosion and a total of 4,000 deaths due to increased cancer risk.
• Energy Conversion Steam Turbine Nuclear fission GeneratorNuclear energy Heat energy Kinetic energy Electrical energy (energy in (from nuclear (steam turns (conversion by uranium) fission) turbine) generator)
• Mechanisms Steam Turbine Nuclear Generator fissionNuclear fission As a result, The heat turns Generator reactor splits large the water into converts the nuclei of amount of steam which kinetic energy uranium or heat is eventually turns to electrical plutonium produced the turbines energy
• Advantages of Nuclear Disadvantages of Nuclear Energy Energy• clean because no • nonrenewable – it will pollutants produced finish after using it up.• uranium used in nuclear • produces radioactive reactors is inexpensive waste, which needs to compared to the be carefully handled and amount of electricity it stored. can produce
• Conversion of energy Laws of conversion of energy“ Energy cannot be created and destroyed only change from one type to another ” Chemical energy Light energy Heat energy (fuel or coal) (fire) (hot)
• Electrical AppliancesElectrical Electrical Kinetic Heat energy energy energy
• Kinetic Sound +Electrical Electrical energy + Light + energy energy sound Heat
• Solar Cells Light (from the Sun) Electrical energy (conversion by the photovoltaic cells)