Heat and Temperature

1. Heat and Temperature Preview • Understanding Concepts • Reading Skills • Interpreting Graphics

2. Understanding Concepts 1. What method of transferring energy carries energy from the sun to Earth? A. conduction B. convection C. insulation D. radiation

3. Understanding Concepts, continued 1. What method of transferring energy carries energy from the sun to Earth? A. conduction B. convection C. insulation D. radiation

4. Understanding Concepts, continued 2. A certain amount of energy is added to an iron bar. Afterward, the iron bar glows white-hot and gives off energy both as light and heat. What does this energy release indicate about the particles of iron in the bar? F. They have high kinetic energy. G. They have low kinetic energy. H. They are being emitted from the bar. I. They are changing phase.

5. Understanding Concepts, continued 2. A certain amount of energy is added to an iron bar. Afterward, the iron bar glows white-hot and gives off energy both as light and heat. What does this energy release indicate about the particles of iron in the bar? F. They have high kinetic energy. G. They have low kinetic energy. H. They are being emitted from the bar. I. They are changing phase.

6. Understanding Concepts, continued 3. What happens to the energy that is not used when an engine is less than 100% efficient? A. It is destroyed during combustion. B. It is used to decrease entropy. C. It is converted to heat. D. It is converted to matter.

7. Understanding Concepts, continued 3. What happens to the energy that is not used when an engine is less than 100% efficient? A. It is destroyed during combustion. B. It is used to decrease entropy. C. It is converted to heat. D. It is converted to matter.

8. Understanding Concepts, continued 4. Mercury has a specific heat of 140 J/kg·K. How much energy is required to raise the temperature of 2 kg of mercury by 1 °C?

9. Understanding Concepts, continued 4. Mercury has a specific heat of 140 J/kg·K. How much energy is required to raise the temperature of 2 kg of mercury by 1 °C? Answer: 140 J/kg•K × 2 kg × 1 K = 280 J

10. Understanding Concepts, continued 5. If the rate of expansion of mercury increased as it was heated, in what way would mercury thermometers have to be different so that the same temperature range could be accurately read from them?

11. Understanding Concepts, continued 5. If the rate of expansion of mercury increased as it was heated, in what way would mercury thermometers have to be different so that the same temperature range could be accurately read from them? Answer: Mercury thermometers would have to be longer.

12. Reading Skills CLIMATE IS ALL ABOUT THE OCEANS The high specific heat of the ocean plays a central role in shaping Earth’s climate. Earth’s atmosphere cannot store as much energy as the oceans can. The heat energy that can be stored in the entire atmosphere can be stored in a layer of the ocean just 3.2 m deep. The specific heat of dry land is less than 25% that of sea water. The land surface also has a low conductivity. As a result, only the top 2 m or so of the land typically plays an active role in energy storage and release. Therefore, land plays a much smaller role in the storage of energy than the ocean does. Major ice sheets, such as those over Antarctica and Greenland, have a large mass. Ice has a higher heat conductivity than land does, but as on land, the transfer of energy as heat occurs primarily through conduction.

13. Reading Skills, continued CLIMATE IS ALL ABOUT THE OCEANS, continued Major ice sheets, such as those over Antarctica and Greenland, have a large mass. Ice has a higher heat conductivity than land does, but as on land, the transfer of energy as heat occurs primarily through conduction. The key difference between ice and water is that energy as heat can transfer through water by convection because water is a fluid. Convection can occur faster than conduction, so ice sheets and glaciers do not play a major role in energy storage and transfer. 6. Which characteristic makes the ocean play such a major role in shaping Earth’s climate? F. the mass of the ocean H. the specific heat of the ocean G. the area of the ocean I. the conductivity of the ocean

14. Reading Skills, continued CLIMATE IS ALL ABOUT THE OCEANS, continued Major ice sheets, such as those over Antarctica and Greenland, have a large mass. Ice has a higher heat conductivity than land does, but as on land, the transfer of energy as heat occurs primarily through conduction. The key difference between ice and water is that energy as heat can transfer through water by convection because water is a fluid. Convection can occur faster than conduction, so ice sheets and glaciers do not play a major role in energy storage and transfer. 6. Which characteristic makes the ocean play such a major role in shaping Earth’s climate? F. the mass of the ocean H. the specific heat of the ocean G. the area of the ocean I. the conductivity of the ocean

15. Reading Skills, continued 7. Summarize how energy as heat is transferred through different parts of Earth’s surface by conduction and convection.

16. Reading Skills, continued 7. Summarize how energy as heat is transferred through different parts of Earth’s surface by conduction and convection. Answer: Conduction of heat occurs through the Earth’s solid surface, and convection occurs through the ocean.

17. Interpreting Graphics The graphic below shows energy transfer above a campfire. Use this graphic to answer questions 8–10. 8. What form of energy transfer is represented by this illustration? A. conduction B. convection C. insulation D. radiation

18. Interpreting Graphics The graphic below shows energy transfer above a campfire. Use this graphic to answer questions 8–10. 8. What form of energy transfer is represented by this illustration? A. conduction B. convection C. insulation D. radiation

19. Interpreting Graphics 9. In what form of energy transfer other than the form represented by this illustration does the fire participate? F. conduction G. convection H. insulation I. radiation

20. Interpreting Graphics 9. In what form of energy transfer other than the form represented by this illustration does the fire participate? F. conduction G. convection H. insulation I. radiation

21. Interpreting Graphics 10. Which of the following principles of energy transfer causes the flow of air shown in the illustration to be circular? A. Warmer air descends. B. Cooler air descends. C. Warm air and cool air are attracted to each other. D. Warm air and cool air tend to repel each other.

22. Interpreting Graphics 10. Which of the following principles of energy transfer causes the flow of air shown in the illustration to be circular? A. Warmer air descends. B. Cooler air descends. C. Warm air and cool air are attracted to each other. D. Warm air and cool air tend to repel each other.