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Introduction |
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For a layman the term 'work' implies any activity resulting in muscular or mental exertion. |
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Work and Measurement of Work |
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Work is said to be done when a force acts on an object and the point of application of the force moves in the direction of force. |
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SI Unit of Work |
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One joule is the work done when the point of application of a force of one newton moves through a distance of one metre in the direction of force. |
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Energy |
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Energy is the capacity to do work. Energy is measured by the amount of work that a body can do. Therefore, SI unit of energy is also joule. |
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Kinetic Energy |
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Kinetic energy is defined as the energy possessed by an object by virtue of its motion. |
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Momentum |
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Momentum of the body is defined as the product of its mass and the velocity. |
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Potential Energy |
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Potential energy of an object can be defined as the energy possessed by the object by virtue of its position or condition. |
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Law of Conservation of Energy |
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Law of conservation of energy states that the energy can neither be created nor destroyed but can be transformed from one form to another. |
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Power |
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As energy is the capacity to do work, power can also be defined as energy consumed in unit time. |
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Commercial Unit of Energy |
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The SI unit joule is too small to express very large quantities of energy. Hence we use a bigger unit called kilowatt hour (kWh) to express energy. |
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Summary |
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Law of conservation of energy states that energy can neither be created nor destroyed but can be transformed from one form to another. |
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Question and Answers |
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Multiple Choice Questions |
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