Calculating Efficiency. Efficiency (%) = Useful Energy Out x 100 Total Energy In Questions 1) A light bulb takes in 30J of energy per second. It transfers 3J as useful light energy and 27J as heat energy. Calculate the efficiency. 2) A kettle takes in 2000J of energy per second. It transfers 1500J as useful heat energy and 500J is wasted as sound energy. Calculate the efficiency of the kettle. Remember: In the exam they may not
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Potential Energy Potential Energy is a type of energy that does not involve motion. It is the energy that is stored up. The more work done to change an object’s position or shape‚ the more potential energy it has. For example‚ a person on a ladder has more potential energy than a person on the ground because they have done more work to get up there. Kinetic Energy Kinetic Energy is the energy of motion. The more work an object has done‚ the more kinetic energy it has. the amount of kinetic
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2008 Energy conservation is the elimination or reduction of energy we and waste every. Energy is a very important to our society. We use energy for everything transportation‚ cooking‚ heating and cooling‚ manufacturing‚ lighting‚ and entertainment. Energy is the vital force powering business‚ manufacturing‚ and the transportation of goods and services to serve the American and world economies. Can you imagine what life would be like if we did energy? Every year the United
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Why should we save energy in schools? Saving energy leads to reduce carbon emissions‚lower costs and conserves the supplies we have.They are also working in support with high schools to support energy efficiency."We believe energy efficiency is the cheapest and cleanest form of "new" energy the world has." - energy efficiency unit of Chevron.Even though energy suppliers want your business‚ they are looking for more of an investment instead of wasting energy when it isn’t necessary. They believe
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Renewable Energy is Best Michelle Johnson HUM/111 March 26‚ 2011 L. Flemister Renewable Energy is best America’s dependency on foreign oil is costing us more than just money; it costs us our clean air and potentially thousands of jobs in America. Our nation needs to create its own renewable energy. The dependency on other countries is crippling our economy. Drilling for oil in the United States is not the answer. We need to take better care of our planet and that each of us must
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Energy is the ability to do work. It is important because every object we produce requires energy; for example transport‚ growth‚ and development. Humans and all other things get energy from the sun. Some forms of energy are kinetic‚ potential‚ thermal‚ chemical‚ electrical‚ and mechanical. Kinetic energy is the energy of motion. Potential energy is the energy which results from a position or configuration. Thermal‚ or heat‚ energy is the energy a substance or system has related to its temperature
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Dark energy what is it? Dark energy is a unknown energy said to take up 70 percent of the universe. The energy is a repulsive gravitational effect that is causing the universe to accelerate out-ward. No one knows exactly what dark energy is or where it comes from. Dark Energy is a new idea. Little is known about dark energy‚ yet it takes up a huge amount if the universe. Scientist were able to show the universe was expanding at an accelerated rate by measuring the red-shift of an object by comparing
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issues in today’s world is that of energy sources to power an increasing global demand. Traditionally‚ humans have converted energy from natural resources like coal and natural gas for use. However‚ these sources of energy are both nonrenewable and cause large amounts of pollution. As we progress through the 21st century‚ renewable energy sources like solar and wind energy will see increased use to replace traditional sources. One of these sources‚ wind energy‚ is seeing a rise in development because
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Alternative Energy Alternative Energy Alternative energy refers to energy sources that have no undesired consequences such for example fossil fuels‚ nuclear energy and falling water. Fossil fuels are coal‚ petroleum and natural gas. There are some characteristics of the fossil fuels that made the concept of alternative energy come into place. (Alternative Energy) One of the fossil fuels‚ Petroleum‚ forms a thin film around the grains of the rock where it formed. Pressure from the overlying rock
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Renewable energy is the need of the hour It is the year 2050‚ Earth is so polluted‚ vision is obscured by smog‚ lakes and streams are poisoned. Oh! What a terrible sight. This may become a reality‚ if we keep using non-renewable energy resources. Hello there! A very good morning and I am Pranav Athreya and you have guessed it right‚ I am speaking for the topic Renewable energy is the need of the hour. At present‚ the main energy sources used are non-renewable fossil fuels like coal‚ petroleum‚ and
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