Doodle Science teaches you high school physics in a less boring way in almost no time!
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Different types of energy can be transferred from one type to another. You can see that a car engine transfers chemical energy, which is stored in the fuel, into kinetic energy in the engine and wheels so it can get you from A to B. In a lamp the electrical input is converted into light energy. However not all the energy put in is turned into useful energy, some of it is turned into energy we don’t need such as heat.
Sankey diagrams summarise all the energy transfers taking place in a process. The thicker the arrow, the greater the amount of energy involved. This Sankey diagram for an electric lamp shows that most of the electrical energy is transferred as heat rather than light. This means it’s very inefficient. We can calculate efficiency using this simple formula, useful energy, in this case 10J divided by the total energy input, which is 100J, which gives us an efficiency of 0.1 or 10% if you times it by 100.
Doodle Science teaches you high school physics in a less boring way in almost no time!
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Renewable energy resources are being developed because we are running out of fossil fuels at an exponential rate.
The wind is produced as a result of giant convection currents in the Earth’s atmosphere, which are driven by heat energy from the sun. Wind turbines use the wind to drive turbines directly. The blades are connected to a housing, which contains gears linked to a generator. As the wind blows, it transfers some of its kinetic energy to the blades, which turn and drive the generator. The advantages are that there are no fuel costs and no harmful pollutant gases are produced. However, they depend on wind, if there is no wind, there’s no electricity.
Like the wind, water can be used to drive turbines directly. Wave machines use the kinetic energy in this movement to drive electricity generators. Another way of using the water is to build a tidal barrage over a river estuary to make use of the kinetic energy in the moving water. The barrage contains electricity generators, which are driven by the water rushing through tubes in the barrage. Hydroelectric power stations are dams built across a river valley. The water high up behind the dam contains gravitational potential energy. This is transferred to kinetic energy as the water rushes down through tubes inside the dam. The moving water drives electrical generators, which may be built inside the dam. Water produced energy is good because no harmful polluting gases are produced and tidal barrages and hydroelectric power stations are very reliable and can be easily switched on. However, tidal barrages destroy the habitat of estuary species and hydroelectricity dams flood farmland and push people from their homes.
Doodle Science teaches you high school physics in a less boring way in almost no time!
Script:
Fossil fuels are non-renewable energy resources; these are coal, oil and natural gas. They were formed from the remains of living organisms millions of years ago and they release heat energy when they are burned. This heat is used to turn water into steam, which is used to turn a turbine, which then drives a generator to generate electricity. There are downsides however, fossil fuels release sulphur dioxide and carbon dioxide which lead to acid rain and an increase in global warming.
Another form of non-renewable energy is Nuclear. The main nuclear fuels are uranium and plutonium. The nuclei of these large atoms are split in a process called nuclear fission to release a great deal of heat. The heat energy is again used to boil water. The kinetic energy in the expanding steam spins turbines, which then drive generators to produce electricity. Unlike fossil fuels, nuclear fuels do not produce carbon or sulphur dioxide. However, they do have the risk of a fault where large amounts of radioactive material could be released into the environment such as the disaster of Chernobyl in 1986. Video Rating: / 5
