1. Energy 3.1 Energy exists in different forms. 3.2
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Energy
the BIG idea
Energy has different forms, but it is always conserved.
3.1
Energy exists in different forms.
3.2
Energy can change forms but is never lost.
3.3
Technology improves the ways people use energy.
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2. Energy exists in different forms.
3.1
Energy exists in different forms.
• Energy is the ability to cause a change.
• Different forms of energy produce changes in different ways.
energy
kinetic energy
• Kinetic energy depends on mass and speed.
potential energy
High Speed
Low Speed
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3. Energy exists in different forms.
3.1
Energy exists in different forms.
• Energy is the ability to cause a change.
• Different forms of energy produce changes in different ways.
energy
kinetic energy
• Kinetic energy depends on mass and speed.
potential energy
• Potential energy depends on position and chemical composition.
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4. 3.1 energy Energy exists in different forms.
kinetic energy
The ability to do work or to cause a change. For example, the energy of a moving bowling ball knocks over pins; energy from food allows animals to move and to grow; and energy from the Sun heats Earth’s surface and atmosphere, which causes air to move.
potential energy
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5. 3.1 kinetic energy Energy exists in different forms.
The energy of motion. A moving object has the most kinetic energy at the point where it moves the fastest.
potential energy
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6. 3.1 potential energy Energy exists in different forms.
kinetic energy
Stored energy; the energy an object has due to its position, molecular arrangement, or chemical composition.
potential energy
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7. Energy can change forms but is never lost.
3.2
Energy can change forms but is never lost.
• Energy often needs to be transformed in order to produce a useful form of energy.
law of conservation of energy
• The law of conservation of energy states that energy is never created or destroyed.
energy efficiency
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8. Energy can change forms but is never lost.
3.2
Energy can change forms but is never lost.
• Energy often needs to be transformed in order to produce a useful form of energy.
law of conservation of energy
• The law of conservation of energy states that energy is never created or destroyed.
energy efficiency
• Energy can be transformed in many different ways, including from potential energy (PE) to kinetic energy (KE) and back again.
VISUALIZATION
Investigate the relationship between potential energy and kinetic energy.
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9. law of conservation of energy
3.2
Energy can change forms but is never lost.
law of conservation of energy
law of conservation of energy
energy efficiency
A law stating that no matter how energy is transferred or transformed, it continues to exist in one form or another.
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10. 3.2 energy efficiency Energy can change forms but is never lost.
law of conservation of energy
energy efficiency
energy efficiency
A measurement of usable energy after an energy conversion; the ratio of usable energy to the total energy after an energy conversion.
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11. Technology improves the ways people use energy.
3.3
Technology improves the ways people use energy.
• Different forms of technology are being developed and used to improve the efficiency of energy conversions.
solar cell
• Solar cells convert sunlight into electrical energy.
• New solar cells convert light into electrical energy more efficiently than those in the past
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12. Technology improves the ways people use energy.
3.3
Technology improves the ways people use energy.
• Different forms of technology are being developed and used to improve the efficiency of energy conversions.
solar cell
• Solar cells convert sunlight into electrical energy.
• New solar cells convert light into electrical energy more efficiently than those in the past
VISUALIZATION
Observe how solar cells produce electricity.
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13. 3.3 solar cell Technology improves the ways people use energy.
A device that converts the energy of sunlight into electrical energy.
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14. 3.1 Energy exists in different forms.
I. Energy exists in different forms.
energy
A. Different forms of energy have different uses.
kinetic energy
1. Energy
potential energy
2. Forms of Energy
B. Kinetic energy and potential energy are the two general types of energy.
1. Kinetic Energy
2. Potential Energy
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15. Energy can change forms but is never lost.
3.2
Energy can change forms but is never lost.
II. Energy can change forms but is never lost.
law of conservation of energy
A. Energy changes forms.
1. Conversions Between Potential Energy and Kinetic Energy
energy efficiency
2. Using Energy Conversions
B. Energy is always conserved.
C. Energy conversions may produce unwanted forms of energy.
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16. Technology improves the ways people use energy.
3.3
Technology improves the ways people use energy.
III. Technology improves the ways people use energy.
solar cell
A. Technology improves energy conversions.
1. Efficient Lights
2. Efficient Cars
B. Technology improves the use of energy resources.
1. Solar Energy
2. Wind Energy
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Investigate the relationship between potential energy and kinetic energy.
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Observe how solar cells produce electricity.
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