Unit 2 Lesson 1 Introduction to Energy Copyright © Houghton Mifflin Harcourt Publishing Company

Get Energized! What are two types of energy? Unit 2 Lesson 1 Introduction to Energy Get Energized! What are two types of energy? Energy is the ability to cause change. Energy takes many different forms and causes many different effects. There are two general types of energy: kinetic energy and potential energy. Copyright © Houghton Mifflin Harcourt Publishing Company

What are two types of energy? Unit 2 Lesson 1 Introduction to Energy What are two types of energy? Kinetic energy is the energy of an object that is due to motion. All moving objects have kinetic energy. The amount of kinetic energy an object has depends on its mass and speed. Kinetic energy increases as mass increases and as speed increases. Copyright © Houghton Mifflin Harcourt Publishing Company

What are two types of energy? Unit 2 Lesson 1 Introduction to Energy What are two types of energy? Potential energy is the energy that an object has due to its position, condition, or chemical composition. Potential energy that is the result of an object’s position is called gravitational potential energy. Gravitational potential energy increases as the object’s height or mass increases. Copyright © Houghton Mifflin Harcourt Publishing Company

What are two types of energy? Unit 2 Lesson 1 Introduction to Energy What are two types of energy? A change in the condition of an object affects its potential energy. Stretching a rubber band increases its potential energy. Chemical potential energy depends on chemical composition. As bonds break and new bonds form between atoms during a chemical change, energy can be released. Copyright © Houghton Mifflin Harcourt Publishing Company

Can objects have potential and kinetic energy at the same time? Unit 2 Lesson 1 Introduction to Energy Can objects have potential and kinetic energy at the same time? An object can have both potential and kinetic energy at the same time. A skater has kinetic energy as he moves down a ramp and potential energy due to his position on the ramp. Copyright © Houghton Mifflin Harcourt Publishing Company

In Perfect Form What forms can energy take? Unit 2 Lesson 1 Introduction to Energy In Perfect Form What forms can energy take? Kinetic energy and potential energy are two types of energy that can come in many different forms. Some common forms of energy include mechanical, sound, electromagnetic, electrical, chemical, thermal, and nuclear energy. Energy is expressed in joules (J). Copyright © Houghton Mifflin Harcourt Publishing Company

What forms can energy take? Unit 2 Lesson 1 Introduction to Energy What forms can energy take? Mechanical energy is the sum of an object’s kinetic energy and potential energy. It is the energy of position and motion. Sound energy is kinetic energy caused by the vibration of particles in a medium such as steel, water, or air. Copyright © Houghton Mifflin Harcourt Publishing Company

What forms can energy take? Unit 2 Lesson 1 Introduction to Energy What forms can energy take? Electromagnetic energy is transmitted through space in the form of electromagnetic waves. These waves are caused by the vibration of electrically charged particles. Electromagnetic waves include visible light, X-rays, and microwaves. Copyright © Houghton Mifflin Harcourt Publishing Company

What forms can energy take? Unit 2 Lesson 1 Introduction to Energy What forms can energy take? Electrical energy is the energy that results from the position or motion of charged particles. Chemical energy is a form of potential energy. The amount of chemical energy in a molecule depends on the kinds of atoms and their arrangement. Copyright © Houghton Mifflin Harcourt Publishing Company

What forms can energy take? Unit 2 Lesson 1 Introduction to Energy What forms can energy take? The thermal energy of an object is the kinetic energy of its particles. The faster the molecules in an object move, and the more particles the object has, the more thermal energy it has. Heat is the energy transferred from an object at a higher temperature to an object at a lower temperature. Copyright © Houghton Mifflin Harcourt Publishing Company

What forms can energy take? Unit 2 Lesson 1 Introduction to Energy What forms can energy take? The nucleus of an atom is the source of nuclear energy. When an atom’s nucleus breaks apart, or when the nuclei of two small atoms join together, energy is released. Copyright © Houghton Mifflin Harcourt Publishing Company

Space Weather and Technology Unit 2 Lesson 1 Introduction to Energy Space Weather and Technology Space weather includes any activity happening in space that might affect Earth’s environment. Space weather can damage satellites and interrupt phone signals and signals to Global Positioning System (GPS) receivers. Auroras are caused by electrically charged particles of solar winds hitting Earth’s magnetic field. They can interrupt airplane communications. Copyright © Houghton Mifflin Harcourt Publishing Company

Transformers What is an energy transformation? Unit 2 Lesson 1 Introduction to Energy Transformers What is an energy transformation? An energy transformation takes place when energy changes from one form into another form. Any form of energy can change into any other form of energy. Often, one form of energy changes into more than one form. Copyright © Houghton Mifflin Harcourt Publishing Company

What is an energy transformation? Unit 2 Lesson 1 Introduction to Energy What is an energy transformation? In a flashlight, chemical energy is transformed into electrical energy. The electrical energy is then transformed into light and thermal energy. Copyright © Houghton Mifflin Harcourt Publishing Company 15

Unit 2 Lesson 1 Introduction to Energy Is energy conserved? A closed system is a group of objects that transfer energy only to one another. Energy is conserved in all closed systems. The law of conservation of energy states that energy cannot be created or destroyed. It can only change forms. All of the different forms of energy in a closed system always add up to the same total amount of energy. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 2 Lesson 2 Temperature Copyright © Houghton Mifflin Harcourt Publishing Company

Particle Party What is the kinetic theory of matter? Unit 2 Lesson 2 Temperature Particle Party What is the kinetic theory of matter? The kinetic theory of matter states that all of the particles that make up matter are constantly in motion. Because the particles are in motion, they have kinetic energy. The faster they move, the more kinetic energy they have. Copyright © Houghton Mifflin Harcourt Publishing Company 18

What is the kinetic theory of matter? Unit 2 Lesson 2 Temperature What is the kinetic theory of matter? The motion of the particles is random. The individual particles have different amounts of kinetic energy, but their average kinetic energy takes into account their different random motions. Solids, liquids, and gases have different average kinetic energies. Copyright © Houghton Mifflin Harcourt Publishing Company 19

How do particles move in solids, liquids, and gases? Unit 2 Lesson 2 Temperature How do particles move in solids, liquids, and gases? The kinetic theory of matter explains the motion of particles in solids, liquids, and gases. The particles in a solid do not move around much. Copyright © Houghton Mifflin Harcourt Publishing Company 20

How do particles move in solids, liquids, and gases? Unit 2 Lesson 2 Temperature How do particles move in solids, liquids, and gases? The particles in a liquid move much more freely than the particles in a solid. They slide past and tumble over each other. Copyright © Houghton Mifflin Harcourt Publishing Company 21

How do particles move in solids, liquids, and gases? Unit 2 Lesson 2 Temperature How do particles move in solids, liquids, and gases? The particles in a gas are far apart, move at high speeds, and collide with one another. Copyright © Houghton Mifflin Harcourt Publishing Company 22

Mercury Rising How does temperature relate to kinetic energy? Unit 2 Lesson 2 Temperature Mercury Rising How does temperature relate to kinetic energy? Temperature is a measure of the average kinetic energy of all the particles in an object. The warmer a substance is, the faster its particles move. Copyright © Houghton Mifflin Harcourt Publishing Company 23

How is temperature measured? Unit 2 Lesson 2 Temperature How is temperature measured? There are three common temperature scales. They all measure the average kinetic energy of particles. The scales are called Celsius, Fahrenheit, and Kelvin. Copyright © Houghton Mifflin Harcourt Publishing Company 24

How is temperature measured? Unit 2 Lesson 2 Temperature How is temperature measured? In the Celsius and Fahrenheit scales, temperature is measured in units called degrees. Degrees (°) are equally spaced units between two points. The space between degrees can vary from one scale to another. In the Kelvin scale, no degree sign is used. The unit is just called a kelvin. Temperature is measured with a thermometer. Copyright © Houghton Mifflin Harcourt Publishing Company 25

How is temperature measured? Unit 2 Lesson 2 Temperature How is temperature measured? The Celsius scale is the temperature scale most commonly used around the world. Copyright © Houghton Mifflin Harcourt Publishing Company 26

How is temperature measured? Unit 2 Lesson 2 Temperature How is temperature measured? The Fahrenheit scale is used most commonly in the United States. Copyright © Houghton Mifflin Harcourt Publishing Company 27

How is temperature measured? Unit 2 Lesson 2 Temperature How is temperature measured? The Kelvin scale is used most commonly by physicists. Copyright © Houghton Mifflin Harcourt Publishing Company 28