To expand upon students’ understanding of energy, its many sources, and how it can be transformed into other forms of energy to get work done.
Another Science Netlinks lesson, Converting Energy, is a prerequisite for this lesson. In that lesson, students are first introduced to the concept of energy conversion and develop their basic ideas about energy and how it can be measured. In this lesson, students broaden their ability to identify energy sources, the energy transformation process, and build basic machines/systems that use energy transformations to get work done.
At this level, students should be introduced to energy primarily through energy transformations. In this lesson, students will be given the opportunity to trace where energy comes from (and goes next) in examples that involve several different forms of energy: heat, light, motion of objects, chemical, and so on. This lesson also seeks to address the likely confusion in students' minds between energy and energy sources. Focusing on energy transformations may get around this somewhat. For example, food, gasoline, and batteries obviously get used up. But the energy they contain does not disappear; it is changed into other forms of energy. (Benchmarks for Science Literacy, p. 84.) Be sure to help students recognize this important—yet often confusing—distinction while teaching the lesson.
The most primitive idea to which students will be exposed is that the energy needed for an event must come from somewhere. That should trigger children's interest in asking, for any situation, where the energy comes from and (later) asking where it goes. Where it comes from is usually much more evident than where it goes, because some usually diffuses away as radiation and random molecular motion. (Benchmarks for Science Literacy, p. 84.)
How energy transformation relates to the concept of work, or means to get things done, is also addressed in this lesson. For young students, it may be enough at first to convince them that energy is needed to get physical things to happen and that they should get in the habit of wondering where the energy came from. Then, as they study physical, chemical, and electrical systems, many opportunities arise for them to see the many different forms energy takes and to find out how useful the energy concepts are. (Benchmarks for Science Literacy, p. 82.)
Research shows that students at this level have a number of misconceptions about energy. For example, students believe energy is associated only with humans or movement, is a fuel-like quantity that is used up, or is something that makes things happen and is expended in the process. Students rarely think energy is measurable and quantifiable. And, although students typically hold these meanings for energy at all ages, upper elementary-school students tend to associate energy only with living things, in particular with growing, fitness, exercise, and food. In addition, middle- and high-school students tend to think that energy transformations involve only one form of energy at a time. Although they develop some skill in identifying different forms of energy, in most cases their descriptions of energy change focus only on forms that have perceivable effects. Finally, it may not be clear to students that some forms of energy, such as light, sound, and chemical energy, can be used to make things happen. (Benchmarks for Science Literacy, p. 338.)
The Science NetLinks lesson Converting Energy is a prerequisite for this lesson.
Important note: A variety of materials will be needed for each of the system-building projects you assign to your students from the Energy Quest website. The materials you provide will depend on the size of your class, your preferences, and your classroom resources.
Begin by having students review what they have learned about energy and energy sources from the prerequisite Science Netlinks Converting Energy lesson. This will help to reinforce what they have already learned about energy, its various sources, and transforming power to get things done in our everyday lives.
Include in your general discussion review questions such as:
- What is energy? What is it used for?
- Can energy be created? Can it be destroyed?
- Can one kind of energy by changed into another?
- What are some examples of energy being transformed from one form to another?
- What are some of the different types of energy sources?
- What is the difference between potential and kinetic energy?
Next, have students start thinking about machines—like those used at school, at home, in offices, and in the outdoors. Use a number of examples to help students see how machines use different forms of energy to perform tasks and get work done. Then pass out the Energy Transformations student sheet and have them fill it out (preferably with at least one example of a machine that uses solar, mechanical, electrical, chemical, light, wind, or nuclear energy to perform a task).
When finished, have students discuss their findings. Comprehension questions may include:
- What is another way you could perform that task by using a different energy source or machine?
- What energy source do you think powers most of the machines people use outdoors?
- Think about the machines that are used at home. What energy source powers most of them?
- What would life be like if we didn't have different energy sources or machines to help us get things done?
To further clarify their understanding of energy sources and how machines and other systems transform them into other forms of energy, have students use their Power Play student esheet to visit the Energy Information Administration's Using and Saving Energy website. This resource provides very detailed information and statistics on the types of energy and machines that are used to support people's homes, commercial buildings, transportation, and industry and manufacturing. Have students use their esheet as a guide through this resource. As they read through each of the four major subjects, have them answer the questions on their Uses of Energy student sheets. (Answers to these questions can be found on the Uses of Energy teacher answer sheet.)
When finished, have students discuss their answers with the class. Also, go through each subsection as a class and encourage students to make connections between the energy sources and the machines or jobs that they power. For example, in the Commercial Building section, have students think about the types of machines that would fall under the "cooking" or "office equipment" categories—and the types of energy that would power them.
Next, using their student esheet, students should go to Power Play, which is an interactive activity that will enable them to focus on the actual transformation of energy from one form to another. Moreover, they will learn to build machines by connecting various parts on the screen so that the machines link a power source with a job that needs to get done. Students will have to put the parts of the machine together in the right order to get the machine to work properly.
Before they begin, have students click on and read the "Learn More" and "How to Play" sections. Discuss what they have read and pose comprehension questions such as:
- What do machines need to work?
- Can you think of any machines that work without energy?
- What kinds of things can we do with energy?
Allow students to play the activity many times until you feel they have a good understanding about what is happening. Then take the class through each of the four machine-building scenarios and discuss the energy transformation process. Have students pay particular attention to the input energy and the output task, as well as to how the different parts of the system relate to each other. Ask students to complete the How Does It Run? student sheet as they work through the interactive. Discussion questions might include:
- What power sources are used to make these machines run?
- What tasks do the machines perform?
- Is energy either created or destroyed in these processes?
- What observations can you make about the different parts and how they work together to run the machine?
- How did you know which part to use when building the machine?
- Describe what happens to the energy as it moves from its source to the work it performs.
- Think of a machine that you used this morning. What energy source(s) made it work? What task did it help you complete?
Now explain to students that they will be given the opportunity to build their own machines, or systems, that transform energy to complete a job. Divide the class into small groups and assign to each group one of the following machine-building projects from the Energy Quest website. (Please note that some of these projects may require adult supervision.)
Once the groups have finished building their machines (systems), have them complete an Energy Projects student sheet. This will serve as a basis for their presentations to the class.
During the presentations, encourage the presenters to explain how their machines work and transform energy and what they learned from building them. Class members should be encouraged to ask questions about:
- How the machine works
- How energy is transformed from one form to another
- How the machine parts relate to each other
- How this kind of transformed energy is used to benefit society
- What they learned during the development process
For a related Science NetLinks lesson see Harnessing Solar Energy.
The Energy Information Administration's Kid's Page offers numerous opportunities for students to gain a more in-depth understanding about energy. For instance, the Kids Corner section provides information on energy sources (e.g., renewable and non-renewable), the Pioneers in Energy who made significant advances in energy and science, and Energy News That You Can Use. Other sections include Classroom Connection, Energy Quiz, Energy Fun & Games, Milestones, and Online Resources.
By visiting the interesting and colorful Learning Power website, students can gain a greater understanding of electricity and how power utilities work. It is meant to explain "how the juice gets to the plug." Activities and information are presented in the three main sections—Teacher Stuff, Homework Busters, and Understanding Utilities.