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Description
Flashcards by Ahmed Almohammed, updated more than 1 year ago
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Created by Ahmed Almohammed
over 8 years ago
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| Question | Answer |
| What is Energy transfer? | Energy transfer is the term given to the energy that is passed from one object to another. |
| How is energy passed on from one object to another? | Energy is transferred from one object to another when a reaction takes place. Energy comes in many forms and can be transferred from one object to another as heat, light, or motion. |
| When you kick a ball, what energy is transferred from your foot to the ball? | When you kick a ball, kinetic energy is transferred from your foot to the ball. |
| What are the energy changes that happen when a glass falls off a table? | |
| How does a solar fan work? | A solar cell converts light energy from the sun into electrical energy.This electrical energy is converted into the kinetic energy of the blades, as well as sound and heat energy produced by the solar fan. |
| What does the law of conservation of energy state? | The law of conservation of energy states that energy can never be created or destroyed. It can only be converted from one form to another. |
| If energy is never lost, were do you think it is gone? | Energy can never get "lost" or it can never be destroyed. It can only be converted into other forms of energy and transformed into other objects. |
| What is the supplied, useful and wasted energy of the following objects (Toaster) | Supplied = Electrical Useful = Heat Wasted = Light and heat that doesn't reach the toast. |
| Electric cooker | Supplied = Electrical Useful = Heat Wasted = Light and heat that doesn't reach the object that needs to be heated |
| Electric toothbrush | Supplied = Electrical energy Useful = Kinetic energy Wasted = Heat and sound energy |
| When you push a trolley, what happens to the kinetic energy that is transferred to it? | Friction between its wheels and the ground produces heat.Eventually, the car will stop moving because all the kinetic energy have been converted into heat energy. |
| What is energy efficiency? | Energy efficiency is a measure of how much input energy is converted into useful output energy. |
| How do we know if an object is energy efficient or inefficient? | If most of the input energy is converted into useful output, then the device is energy efficient. If a lot of the input energy is wasted, then the object is inefficient. |
| What are renewable energy sources? | Renewable energy sources are energy sources that are unlimited in supply and can be used over and over again. |
| Why is it that only small amount of the original chemical potential energy of a fossil fuel is converted into the useful energy needed? | This happens because heat energy is lost at each step of generating and delivering the electricity. |
| Which of the following is an efficient energy conversion -: Driving a car or Riding a bike | Riding a bike, because in driving a car, for every 100J of chemical energy supplied, only 25J of kinetic energy is produced. While riding a bike, up to 95KJ out of every 100KJ of energy that your muscles supply are converted into kinetic energy. |
| What is the difference between useful and wasted energy? | Wasted energy is energy that is transferred into unuseful energy, while useful energy is energy that is transferred into a necessary and wanted energy. |
| What is the input and output of the following objects -: (CAR) | Input = Chemical energy Output = -Kinetic energy -Sound energy -Heat energy |
| (iPod) | Input = Chemical energy Output = -Electrical energy -Sound energy -Heat energy |
| What are some energy conversions? |
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