Section 15.1 Energy and Its Forms (pages )

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1 Section 15.1 and Its Forms (pages ) This section describes how energy and work are related. It defines kinetic energy and potential energy, and gives examples for calculating these forms of energy. It also discusses examples of various types of energy. Reading Strategy (page 446) Building Vocabulary As you read, complete the concept map with vocabulary terms and definitions from this section. For more information on this Reading Strategy, see the Reading and Study Skills in the Skills and Reference Handbook at the end of your textbook. kinetic energy which is the energy of motion can be potential energy which can be gravitational potential energy elastic potential energy and Work (page 447) is the ability to do work. 1. What is energy? 2. When work is done on an object, is transferred to that object. Circle the correct answer. energy heat height 3. Circle the letter of each sentence that is about work and energy. a. in food is converted into muscle movement. b. Both work and energy are usually measured in joules. c. One joule equals one meter per newton. Kinetic (pages ) 4. The energy of motion is called kinetic energy. 5. Is the following sentence or? You can determine the kinetic energy of an object if you know its mass and its volume. Physical Science Reading and Study Workbook Level B 173

Reading Strategy (page 446) Building Vocabulary As you read, complete the concept map with vocabulary terms and definitions from this section.

2 6. Circle the letter of the formula used to calculate an object s kinetic energy. a. Kinetic energy = 1 mv 2 2 b. Kinetic energy = mv 2 v 2 c. Kinetic energy = m Potential (pages ) 7. What is potential energy? It is energy that is stored as a result of position or shape. 8. Is the following sentence or? The work done by a rock climber going up a cliff decreases her potential energy. 9. An object s gravitational potential energy depends on its, its, and the acceleration due to gravity. Circle the correct answers. height mass size 10. Is the following sentence or? Gravitational potential energy of an object increases as its height increases. 11. The potential energy of an object that is stretched or compressed is known as elastic potential energy. Forms of (pages ) For numbers 12 through 17, write the letter of the form of energy that best matches the description. Descriptions Forms of b 12. stored in gasoline, a coal, and wood 13. The sum of an object s potential a. mechanical energy b. chemical energy energy and kinetic energy, c. electrical energy excluding atomic-scale movements d. thermal energy e 14. Produces the sun s heat and light e. nuclear energy f 15. Travels through space in the form f. electromagnetic energy of waves c d 16. Produces lightning bolts 17. Increases as atoms within an object move faster 174 Physical Science Reading and Study Workbook Level B

The work done by a rock climber going up a cliff decreases her potential energy. 9. An object s gravitational potential energy depends on its, its, and the acceleration due to gravity.

3 Section 15.2 Conversion and Conservation (pages ) This section describes how energy is converted from one form to another and presents the law of conservation of energy. Reading Strategy (page 453) Relating Cause and Effect As you read, complete the flowchart to explain an energy conversion used by some gulls to obtain food. For more information on this Reading Strategy, see the Reading and Study Skills in the Skills and Reference Handbook at the end of your textbook. How Gulls Use Conversions Gull lifts oyster, increasing oyster s gravitational potential energy. The gull drops the oyster, and the oyster s gravitational potential energy is converted into kinetic energy as the oyster falls. (Air resistance can be ignored.) The oyster strikes a rock and breaks, and kinetic energy is converted into thermal energy. The kinetic energy and gravitational potential energy of the oyster are now zero. Conversion (page 454) 1. Is the following sentence or? can be converted from one form to another. 2. When a wind-up toy is set in motion, elastic potential energy that was stored in a compressed spring is converted into the of the toy s moving parts. Conservation of (page 455) 3. What does the law of conservation of energy state? or destroyed. 4. A moving object slows down because friction causes a continual conversion of kinetic energy into. Circle the correct answer. mechanical potential thermal energy energy energy kinetic energy cannot be created Physical Science Reading and Study Workbook Level B 175

For more information on this Reading Strategy, see the Reading and Study Skills in the Skills and Reference Handbook at the end of your textbook.

4 Conversions (pages ) 5. As an object falls, the gravitational potential energy of the object is converted into kinetic energy. 6. At what point during a pole-vaulter s jump is his gravitational potential energy the greatest? Circle the letter of the correct answer. a. when he leaves the ground b. at his greatest height c. when he hits the ground 7. Circle the letter of the type of energy that increases as the pole bends before it propels a pole-vaulter up into the air. a. kinetic energy b. mechanical energy c. elastic potential energy 8. Is the following sentence or? For a mechanical change in an isolated system, the mechanical energy at the beginning equals the mechanical energy at the end of the process, as long as friction is negligible. 9. Tell whether the following situations illustrate kinetic energy, potential energy, or both. What Type of Is It? Situation A stationary wind-up toy with a compressed spring A descending roller coaster car A skier poised to take off at the top of a hill A car driving on a flat road A vibrating guitar string and Mass (page 459) Form of 10. Circle the letters of each correct sentence. What does Einstein s equation imply about mass and energy? a. Mass and energy are equivalent. b. Mass and energy are never created. c. Mass and energy can be converted to each other. Potential energy Both Potential energy Kinetic energy Both 176 Physical Science Reading and Study Workbook Level B

when he hits the ground 7. Circle the letter of the type of energy that increases as the pole bends before it propels a pole-vaulter up into the air. a. kinetic energy b. mechanical energy c.

5 Section 15.3 Resources (pages ) 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 Strategy, see the Reading and Study Skills in the Skills and Reference Handbook at the end of your textbook. Heading Nonrenewable energy resources Renewable energy resources Conserving energy resources Main Idea Nonrenewable energy resources include oil, natural gas, and coal. They exist in limited quantities. Renewable energy resources include hydroelectric, solar, geothermal, wind, biomass, and nuclear fusion. resources can be conserved by reducing energy needs and by increasing the efficiency of energy use. Nonrenewable Resources (page 462) 1. What are nonrenewable energy resources? 2. List three examples of nonrenewable energy resources. a. b. c. Coal 3. Circle the letter of each resource that is considered to be a fossil fuel. a. tree b. oil c. coal 4. Is the following sentence or? Although fossil fuels are evenly distributed throughout Earth, they only represent ten percent of total energy consumed. Renewable Resources (pages ) 5. An energy resource that can be replaced in a reasonably short period of time is called a(n) resource. They are resources that exist in limited quantities and, once used, cannot be replaced except over the course of millions of years. Oil Uranium renewable Physical Science Reading and Study Workbook Level B 177

6 6. Circle the letter of each sentence that is about renewable energy resources. a. Wind and solar energy are both renewable energy resources. b. Renewable energy resources are always more efficient than nonrenewable resources. c. Renewable energy resources can be used to generate electricity and to heat homes. 7. Is the following sentence or? One disadvantage of hydroelectric power is that it is among the most expensive energy sources. For numbers 8 through 13, match the letter of each renewable energy source to its description. Description Renewable Sources c 8. Water pumped below ground is converted to steam. a. hydroelectric b. solar f 9. The most likely raw material is c. geothermal hydrogen. d. wind b 10. Mirrors concentrate sunlight to produce electricity. e. biomass d 11. Kinetic energy of moving air is f. nuclear fusion converted into rotational energy of a turbine. a 12. is obtained from flowing water. e 13. Chemical energy stored in wood, peat, and agricultural waste can be converted into thermal energy. 14. Is the following sentence or? Hydrogen fuel cells generate electricity by combining hydrogen with oxygen. Conserving Resources (page 466) 15. Name two practical ways in which people can conserve energy. Accept reasonable responses, such as carpooling, walking or biking on short trips, using more efficient appliances, developing and driving more fuel-efficient cars. 178 Physical Science Reading and Study Workbook Level B

One disadvantage of hydroelectric power is that it is among the most expensive energy sources. For numbers 8 through 13, match the letter of each renewable energy source to its description.

ch 15 practice test Multiple Choice Identify the letter of the choice that best completes the statement or answers the question.

ch 15 practice test Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. 1. Work is a transfer of a. energy. c. mass. b. force. d. motion. 2. What