Chapter 15: Energy

NameChapter 15ClassDateEnergy7. Circle the letter of each sentence that is true about renewableenergy resources.a. Wind and solar energy are both renewable energy resources.b. Renewable energy resources are always more efficient thannonrenewable resources.c. Renewable energy resources can be used to generate electricityand to heat homes.d. Magma generates most renewable energy, either directly orindirectly.8. Describe one energy conversion that takes place during thegeneration of hydroelectric power. Potential energy of water behind a dam is converted tokinetic energy upon release of the water.9. Is the following sentence true or false? One disadvantage ofhydroelectric power is that it is among the most expensive energyfalsesources.For numbers 10 through 15, match the letter of each renewable energy sourceto its description.DescriptionRenewable Energy SourcesctrueConserving Energy Resources(page 466)17. What are two ways that energy resources can be conserved?Energy resources can beconserved by reducing energy needs and by increasing the efficiency of energy use.18. Name two practical ways in which people can conserve energy.Accept reasonableresponses, such as carpooling, walking or biking on short trips, using more efficient appliances,developing and driving more fuel-efficient cars.178Physical Science Reading and Study Workbook Chapter 15 Pearson Education, Inc., publishing as Pearson Prentice Hall. All rights reserved.a. hydroelectric10. Water pumped below groundis converted to steam.b. solarf11. The most likely raw material isc. geothermalhydrogen.d. windb12. Mirrors concentrate sunlight toe. biomassproduce electricity.f. nuclear fusiond13. Kinetic energy of moving air isconverted into rotational energy ofa turbine.a14. Energy is obtained from flowing water.e15. Chemical energy stored in wood, peat,and agricultural waste can be convertedinto thermal energy.16. Is the following sentence true or false? Hydrogen fuel cellsgenerate electricity by combining hydrogen with oxygen.

NameChapter 16ClassDateThermal Energy and HeatSection 16.1 Thermal Energyand Matter(pages 474–478)This section defines heat and describes how work, temperature, and thermalenergy are related to heat. Thermal expansion and contraction of materials isdiscussed, and uses of a calorimeter are explained.Reading Strategy(page 474)Previewing Before you read, preview the figures in this section andadd two more questions in the table. As you read, write answers toyour questions. For more information on this Reading Strategy, see theReading and Study Skills in the Skills and Reference Handbook atthe end of your textbook. Pearson Education, Inc., publishing as Pearson Prentice Hall. All rights reserved.Thermal Energy and MatterQuestions About ThermalEnergy and MatterAnswersWhich has more thermal energy,a cup of tea or a pitcher of juice?A pitcher of juiceWhy did Rumford conclude that heat is nota form of matter? (Fig. 1)The brass was hot enough to make water boilonly during drilling, so the heat must berelated to the motion of the drill.How is specific heat related totemperature? (Fig. 3)The lower a material’s specific heat, the moreits temperature rises when a given amount ofenergy is absorbed by a given mass.Work and Heat(page 474)1. Heat is the transfer of thermal energy from one object to another astemperaturethe result of a difference in.2. Circle the letter of each sentence that is true about heat.a. Heat is a fluid that flows between particles of matter.b. Heat flows spontaneously from hot objects to cold objects.c. Friction produces heat.d. The transfer of thermal energy from one object to another is heat.Temperature (page 475)3. What is temperature?Temperature is a measure of how hot or cold an object is compared toa reference point.4. Is the following sentence true or false? On the Celsius scale, the reference points fortruetemperature are the freezing and boiling points of water.Physical Science Reading and Study Workbook Chapter 16 185

NameChapter 16ClassDateThermal Energy and Heat5. Circle the letter of each sentence that explains what happens whenan object heats up.a. Its particles move faster, on average.b. The average kinetic energy of its particles decreases.c. Its mass increases.d. Its temperature increases.Thermal Energy(page 475)6. What is thermal energy?Thermal energy is the total potential and kinetic energy of all theparticles in an object.mass7. Thermal energy depends upon the,temperaturephase, andof an object.8. Is the following sentence true or false? Two substances can be thesame temperature and have different thermal energies.trueThermal Expansion and Contraction(page 476)9. Is the following sentence true or false? Thermal contraction occurswhen matter is heated, because particles of matter tend to movefalsecloser together as temperature increases.10. Describe thermal expansion and contraction by completing thetable below.Thermal Expansion and ContractionTemperatureSpace BetweenParticlesVolumeThermal expansionIncreasesIncreasesIncreasesThermal contractionDecreasesDecreasesDecreasesSpecific Heat(pages 476–477)11. The amount of heat needed to raise the temperature of one gram ofspecific heatmaterial by one degree Celsius is called.12. Why are you more likely to burn yourself on a metal toy thanon a plastic toy if both have been sitting in the sun? The specific heats of metals tend tobe lower than the specific heats of plastics. If equal masses of metal and plastic absorb the samethermal energy, the metal’s temperature rises more.Measuring Heat Changes(page 478)13. What device is used to measure changes in thermal energy?a calorimeter14. Is the following sentence true or false? A calorimeter uses theprinciple that heat flows from a hotter object to a colder objecttrueuntil both reach the same temperature.186Physical Science Reading and Study Workbook Chapter 16 Pearson Education, Inc., publishing as Pearson Prentice Hall. All rights reserved.Condition

NameChapter 16ClassDateThermal Energy and HeatSection 16.2 Heat andThermodynamics(pages 479–483)This section discusses three kinds of thermal energy transfer and introducesthe first, second, and third laws of thermodynamics.Reading Strategy(page 479)Build Vocabulary As you read this section, add definitions andexamples to complete the table. For more information on this ReadingStrategy, see the Reading and Study Skills in the Skills andReference Handbook at the end of your textbook.Transfer of Thermal EnergyDefinitionsExamplesConduction: transfer of thermal energywith no net transfer of matterFrying pan handle heats upConvection: transfer of thermal energy whenHot air circulating in an ovenparticles of a fluid move from one place to anotherRadiation: transfer of energy by wavesHeating coil of a stove glowsmoving through space Pearson Education, Inc., publishing as Pearson Prentice Hall. All rights reserved.Conduction (pages 479–480)1. The transfer of thermal energy with no overall transfer of matter isconductioncalled.2. Why is conduction slower in gases than in liquids and solids? In conduction, thermalenergy is transferred by collisions between particles, and there are fewer collisions among particlesin a gas than in a liquid or a solid.3. Is the following sentence true or false? Conduction is faster inmetals than in other solids because metals have free electrons thattruetransfer thermal energy.4. Circle the letter of each sentence that is true about conduction.a. Thermal energy is transferred without transfer of matter.b. Matter is transferred great distances during conduction.c. Conduction can occur between materials that are not touching.d. In most solids, conduction takes place as particles vibrate in place.5. Complete the table about conduction.ConductionType of MaterialQuality of ConductionTwo ExamplesThermal conductorConducts thermal energy wellCopper; aluminumThermal insulatorConducts thermal energy poorlyWood; airPhysical Science Reading and Study Workbook Chapter 16 187

NameChapter 16ClassDateThermal Energy and HeatConvection (pages 480–481)6. The transfer of thermal energy when particles of a fluid move fromconvectionone place to another is called.7. Why is temperature higher at the bottom of an oven? When air at the bottom of theoven heats up, it expands, becomes less dense, and cools as it rises. Cooler, denser air sinksand is heated again at the bottom of the oven.8. When a fluid circulates in a loop as it alternately heats up andconvection currentcools down, a(n)occurs.9. Give three examples of convection currents in nature. Ocean currents, weather systems,and movement of hot rock in Earth’s interior are examples of convection currents.Radiation(page 481)10. The transfer of energy by waves moving through space is calledradiation.11. Circle the letter of each sentence that is true about radiation.a. Energy is transferred by waves.b. All objects radiate energy.c. The amount of energy radiated from an object decreases as itstemperature increases.d. The farther away you are from a radiating object, the lessradiation you receive.Thermodynamics(pages 482–483)truehotter14. Thermal energy flows spontaneously fromcolderobjects toones.15. According to the second law of thermodynamics, what musthappen for thermal energy to flow from a colder object to ahotter object? Work must be done on the system.16. Thermal energy that is not converted into work is calledwaste heat.17. Is the following sentence true or false? Scientists have created aheat engine with 100 percent efficiency by reducing thetemperature of the outside environment to absolute zero.false18. Is the following sentence true or false? Matter can be cooled tofalseabsolute zero.188Physical Science Reading and Study Workbook Chapter 16 Pearson Education, Inc., publishing as Pearson Prentice Hall. All rights reserved.12. Thermodynamics is the study of conversions betweenthermal energyand other forms of energy.13. Is the following sentence true or false? Energy cannot be createdor destroyed, but it can be converted into different forms.

NameChapter 16ClassDateThermal Energy and HeatSection 16.3 Using Heat(pages 486–492)This section describes ways in which humans benefit from heat engines,heating systems, and cooling systems. It also discusses how each of thesesystems works.Reading Strategy (page 486)Sequencing As you read, complete the cycle diagram to show thesequence of events in a gasoline engine. For more information on thisReading Strategy, see the Reading and Study Skills in the Skills andReference Handbook at the end of your textbook.Sequence of Events in a Gasoline EngineCompression stroke:Piston compressesthe fuel-air mixture.Intake stroke:Power stroke:Fuel and airenter cylinder.Ignited mixture expandsand pushes the piston.Exhaust stroke: Pearson Education, Inc., publishing as Pearson Prentice Hall. All rights reserved.Exhaust gases leavethe cylinder.Heat Engines(pages 486–487)external combustion engine1. The two main types of heat engines are theinternal combustion engineand the.2. A steam engine is an external combustion engine because it burnsoutsidefuelthe engine.3. Who developed the first practical steam engine?a. James Prescott Jouleb. Thomas Newcomenc. James Wattd. Benjamin Thompson4. How is heat converted into work in a steam engine? Expanding steam pushes againsta piston.5. A heat engine used by most cars in which fuel burns inside theinternal combustion engineengine is called a(n).6. Each upward or downward motion of a piston in an internalstrokecombustion engine is called a(n).Physical Science Reading and Study Workbook Chapter 16 189

NameChapter 16ClassDateThermal Energy and Heat7. Is the following sentence true or false? In a typical car, thecrankshaft produces a linear motion that turns the wheels.false8. Why is it important for an internal combustion engine to havea cooling system? Waste energy produced when the engine does work is transferred to theatmosphere by the cooling system. Without it, the engine would be damaged by thermal expansion.9. Is the following sentence true or false? Gasoline engines operatevery efficiently in converting fuel energy to work.falseHeating Systems (pages 489–490)10. What is a central heating system?It is a system that is used to heat many roomsfrom one location.11. List four energy sources used for central heating systems.Natural gasCoala.b.Electrical energyOilc.d.12. Is the following sentence true or false? In most heating systems,conduction is used to distribute most of the thermal energy.falseMatch each description with the heating system it describes.DescriptionHeating SystemacbCooling Systems(pages 490–492)17. Is the following sentence true or false? Most cooling systems, suchas air conditioners and refrigerators, are heat pumps.true18. A fluid that vaporizes and condenses inside the tubing of a heatrefrigerantpump is called a(n).19. How does a heat pump reverse the normal flow of thermal energy?A heat pumpmust do work on a refrigerant to remove heat from a cold area, such as the inside of a refrigerator.190Physical Science Reading and Study Workbook Chapter 16 Pearson Education, Inc., publishing as Pearson Prentice Hall. All rights reserved.da. hot-water heatingb. steam heatingc. electric baseboard heatingd. forced-air heating13. Water heated by a boilercirculates through radiatorsin each room, transferringthermal energy.14. Fans are used to circulate warmair through ducts to the roomsin a building.15. A hot coil heats air by conductionand radiation.16. This system is often used in olderbuildings or to heat many buildingsfrom a single location.

Section 15.3 Energy Resources (pages 462–466) This section describes types of energy resources and ways to conserve them. Reading Strategy (page 462) Identifying Main Ideas As you read the section, write the main idea for each heading in the table. For more information on this Reading Str