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Description
Flashcards by gizmoalex123, updated more than 1 year ago
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Created by gizmoalex123
over 8 years ago
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| Question | Answer |
| Chemical energy | Energy stored in fuel (including food). This energy is released when chemical reactions take place. |
| Kinetic energy | Energy of a moving object |
| Gravitational potential energy | Energy of an object due to it's position |
| Elastic potential energy | Energy stored in a springy object when we stretch it or squash it |
| Electrical energy | Energy transferred by an electric current |
| Q. When a ball falls in air it loses ______ energy and gains _______ energy. (Fill in the blank) | -Gravitational potential energy -Kinetic energy |
| Q. When an electric heater is switched on, it transfers ______ energy by heating. (Fill in the blank) | -Electrical |
| Useful energy and wasted energy | -Useful energy is energy in the place we want it and in the form we need it. -Wasted energy is energy that is not useful energy. |
| Efficiency equation | Efficiency= useful energy transferred by the device ÷ total energy supplied to the device x 100% |
| An electric motor is used to raise an object. The object gains 60J of gravitational potential energy when the motor is supplied with 200J of electrical energy. Calculate the percentage efficiency of the motor. | =60J ÷ 200J = 0.30 x 100% = 30% |
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