Chapter 6 Energy:
Points to Note:
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Energy is the ability to do work or move something and is measured in joules.
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There are several differnt types of energy:
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Stored Energy is energy not currently in action but is ready for action
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Potential energy is the energy that something has due to its position and stretched e.g a stretched elastic band
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Nuclear energy is the huge amount of stored energy in the nucleus of an atom. This can be released by nuclear fission/fusion
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Chemical energy is the stored energy in substances such as coal or food released through burning or in foods case respiration
Energy in Action:
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Kinetic energy is energy associated with moving objects e.g boulder rolling down a hill
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Heat energy is an example of energy in action. For example, the hotter water particles get in a kettle the more they move
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Light energy causes the veins of a crookes radiometer to turn. It also provides plants with food energy to grow
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Sound energy creates energy through vibrations for example if you placed a glass of water on a loud television the water will move
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Electrical energy comes from moving charges. Its is very convenient into other forms of energy easily
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Magnetic energy has the ability to attract or repel objects. For example a compass uses magnetic energy for showing direction
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Principal of conservation of Energy: Energy can neither be created or destroyed but changed from one form to another
Left: Examples of potential energy
Right: An example of kinetic energy
Fossil Fuels:
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Fossil fuels are a non-renewable source of energy including gas, oil and coal
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Non-renewable sources of energy are sources that will eventually be used up
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Renewable energy is energy that can be used over and over again and will never run out such as solar, wind, nuclear, hydroelectric, biomass, tidal etc
Nuclear Energy:
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In nuclear reactors huge amount of energy are released through Nuclear Fission. In nuclear fission a large nuclei such as uranium is split into two almost equal parts.
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There is a second form of nuclear power known as nuclear fusion. This is done by forcing two light nuclei together. This form of nuclear power releases even more energy than fission. This is the method of energy production used on the sun and the light nuclei used is known as deuterium which is a form of hydrogen
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Fossil fuels were formed millions of years ago from the remains of plants and animals when their remains were squashed and eventually turned into peat and coal
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The method of saving energy is called energy coversion. We can do this by using fiberglass (insulation), double glazed windows and carpets
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When energy is changed from one form to another this is called energy conversion. For example, in a factory coal is burned (chemical energy) produces steam which moves turbines (kinetic)and goes through wires (electrical energy) and turns on a light (light energy)
