ENVIRONMENTAL LITERACY TEACHER GUIDE SERIES Energy Potential A Guide for Teaching Energy in Grades 3 to 8 Energy Comes in Many Forms 1 by Ivan Salinas nergy is responsible for the Energy resources have become the off lights. The pros and cons of all energy world as we know it. It runs our cornerstone of our society. Almost sources, renewable and nonrenewable, CHAPTER E homes, our cars, our bodies, everything we do in our daily lives are debated by politicians and citizens and is virtually changing forms every depends upon energy. Even the water we alike and are often the subject of moment of every single day. The sun drink from our faucets and the plastic discussion on news networks. But what is our constant supply of energy, as and glass containers used to store our does energy mean to scientists, the solar radiation allows plants to grow, leftover foods, require energy. While people who define and study energy? water to evaporate, and wind to move. plant-based energy resources dominated This chapter takes a closer look at what Today, our human communities are the energy landscape just hundreds to energy means and how this meaning is so intimately tied to energy resources thousands of years ago, we now have a similar and different from our everyday we could hardly imagine a world myriad of energy options. The potential use of the word. Basic concepts of energy without them. What was life like just for our energy future is great. The time and energy forms are reviewed as well a few hundred years ago when most for discovering new and innovative as the laws that govern the way energy relied only on wood for fuel and a few energy technologies is now. flows through our world. Lastly, energy luxuries of charcoal and wax? What We talk about energy every day. Some resources will be classified as renewable was the world like just a few thousand people are said to spend energy in their and nonrenewable, a common concept years ago, when only the wood was work, to recover energy after a night’s taught in schools. In fact, many of the available? sleep, or to conserve energy by turning basic concepts discussed in this chapter 10 Energy Comes in Many Forms GRADE STANDARD EEI UNIT scientists look at energy as a “capacity,” they do not describe energy as Grade 3 3 1 a-d something that can be “shared,” “used,” “spent,” or “possessed.” A very important Grade 4 4 1 g concept to remember is that energy Grade 5 5 2 f-g is not created; rather, energy is just transformed, from one form to another. Grade 6 6 3 a-d Our experiences of energy are simply 6 4 a-b 6 5 a us witnessing energy flowing from form 6 6 a-b Energy: It’s Not All the Same to You! to form, happening every day in almost Energy and Material Resources: Renewable or Not? everything we do. When we describe energy in this way, Grade 7 7 1 d it is different from the scientifically Grade 8 8 3 a accepted definition, which says that 8 5 c energy is the “capacity of doing work” (work being defined as “the force exerted receive repeated attention in our schools refer to energy as something we have through a distance”). The science and, therefore, deserve special attention stored inside our bodies. We say, “I don’t definition of energy, while sometimes in any study of energy. These concepts have any more energy to finish this test,” easy for students to remember in science are the foundation for additional study or “I’ll have more energy tomorrow to class, does not readily give meaning to on energy resources in our human finish my homework.” Such a view of their everyday experiences. Students communities. energy depicts it as something we gain must relearn everyday words such or lose. Think about all the meanings as work, force, and energy, for science What Is Energy? of the word energy that your students class that do not match the way they Think about a magazine that describes encounter in a single school day! commonly use these words outside of an artist as focusing her “creative energy” Saying that someone or something school. As a consequence, teaching the from one activity, such as painting, to “has” energy is a metaphor. It is the concept of energy can be a challenge for another, such as a sculpture. This use of everyday meaning we give to the word many teachers. the word energy implies that energy is energy. This metaphor is particularly In the scientific definition of energy, stored in a person’s mind. We commonly problematic for science, because while there are four concepts that need to CHAPTER OVERVIEW Student Thinking: Explaining Energy 13 In the Classroom: Energy is a difficult concept to define but one that we experience every Defining Energy 14 moment of every day. Energy comes in several basic forms, and most of our experiences of energy can point to one of these forms—movement, light, Pictures of Practice: What Is Energy? 15 heat, electricity, and so on. In the Classroom: Energy forms can be classed into two basic types: kinetic or potential. Watching Energy Flow 22 Potential energy may be chemical energy or gravitational energy. Kinetic Student Thinking: energy is the energy of motion, such as the movement of wind or water or Confusing Energy Concepts 23 a person running. One interesting form of energy is heat. Heat, while some- times useful, is not a useable energy resource. Oftentimes heat is considered a Pictures of Practice: Making Sense of Nuclear waste product. In science we use several laws—laws of thermodynamics—to Energy 24 help us understand the dynamics of energy in our world. In this chapter we review forms of energy and how energy transforms following laws of thermodynamics. Energy Comes in Many Forms 11 electric carts, which do the same thing; they move along the aisles while a person shops. The difference is that the person is not exerting the force. The cart has an electric motor that has the capacity to do work. In both of these examples, energy is changing forms. We call this energy transformation. While your students may remember the definition of energy in science class, energy transformations will be what helps students connect the scientific definition to their real-world experience. Energy changing forms is so common that we can find these transformations anywhere at any time, including when reading these pages! There is an energy transformation in your brain that helps your eyes move to scan the pages. There may be a lamp that illuminates your Kicking a soccer ball is a change from potential energy to kinetic energy. environment, changing electrical energy into light and heat energy. When we be clarified: energy, work, force, and and move it along the aisles while you start looking at events happening in distance (or position). Let’s take a closer shop. If it were not for you pushing the world through the lens of energy look at these concepts in an example. the cart, the cart would not move. You transformations, it becomes easier Think of a soccer ball standing on a exert a force on the cart so it changes to help students find meaning and field or a playground. If someone kicks its position. You have the capacity to connections between energy in science the ball, the ball will move. The ball do work. As an option for people with class and energy in their world outside is no longer standing on the field, but disabilities, supermarkets may have of school. rather moving through the air. Thus, the position of the ball is not the same Teaching before and after someone kicked it. Tip The change in the position happened because a person exerted a force on the Help your students better understand the basics behind energy ball when kicking it. Even though the transformation by trying the following activity. Have each student put force was exerted over a small distance a pencil at the edge of his or her desk so it is not moving. Explain how (the kick), it was enough to change the the pencil is exhibiting one type of energy as it is not moving (potential). ball’s position. Next, have students push their pencils off their desks and onto the floor. Kicking the soccer ball is actually Ask students if the type of energy has changed from when it was still. a change in energy—a change from This moving pencil now exhibits kinetic energy. Also discuss the role of potential energy to kinetic energy in students prior to pushing the pencil off of the desk. Where do students the kicker, then to kinetic energy of the get energy from? Students should respond that they get energy to do ball moving. Heat was probably given everyday activities from food they consume. Discuss with students off along the way. how the energy changed, or transformed, from one type (potential) to Another illustration of energy can be another (kinetic) during this exercise. seen when shopping in a supermarket and using a shopping cart. When you get to the supermarket, you grab a cart 12 Energy Comes in Many Forms Explaining Energy umerous studies have looked at student ideas about energy. Educators know that students describe energy in countless ways, but that some interpretations of energy are more common than others. N Following are a few examples of the most common conceptions about energy.