Spring Into Energy

Stephen Van Hook and Tracy Huziak-Clark

Maria lifts up a book from the table. Dietre eats cereal for breakfast. Akisha winds up a toy robot. Jacob puts batteries in a flashlight. These seemingly dissimilar events demonstrate various ways children experience energy daily. You can help primary students make sense of these experiences and build their conceptual understanding of energy with this series of hands-on energy activities. We’ve used these lessons successfully for several years and have been continually impressed with the understandings that students develop as they conduct them.

The lessons focus primarily on elastic, or spring, energy and use a conceptual hook, a simple phrase that identifies the key ideas from the activities. In these lessons, the “hook” is “lift, squeeze, stretch, and twist,” which summarizes some of the ways students can “put” energy in objects. We chose to emphasize spring energy because it is tangible—students can easily observe the spring (or similar objects such as a rubber band) change as they squeeze, stretch, or twist it, and they can feel the spring resist them as they change its shape. See Energy Vocabulary, page 22, for definitions of some key terms.

Lesson One: Where do “things” get energy?

Key idea: Students will begin to distinguish between where something gets its energy and how the object uses its energy.

To engage students, we begin by asking them to help us figure out what’s wrong with a flashlight that isn’t working. When students suggest that maybe it doesn’t have batteries (which is the case), we ask them why the flashlight needs batteries—that is, what does the battery give the flashlight? Usually, a student suggests the word energy, which we describe simply as “the ability for an object to do something.” Then, we ask students what the flashlight does with the energy it gets from the battery. Their answer: It makes light.

The students then explore energy by examining several toys (Figure 1), such as a wind-up robot, a pop-up toy, and a pull-back car, to figure out both where they get their energy and what they use their energy to do. The students then share with the class where each toy gets its energy and what it does with its energy.

Figure 1. Toys used in the unit. Photographs courtesy of the authors.

For each of these toys, the students realize that the energy in the toys comes from them because the toys only work when the students wind them, squeeze them, or push/pull them. For example, the students have to physically turn the key to make the robot move forward. Depending on the toy, students give various answers as to how each toy uses its energy—e.g., to roll, hop, etc. For several toys, students identify more than one way the toy uses its energy (e.g., to move, to make a sound).

Figure 2. Energy sources poster.

We then extend this idea of where things get energy and how they use their energy by discussing where a car (gasoline), a plant (make food using sunlight), a television (electricity), and the students themselves (food) get their energy.

To reinforce the idea that the students get their energy from food, we do the following kinesthetic activity with the students standing in a circle. One of us yawns, pretending to have just woken up. “I don’t have much energy—what can I do? “Eat breakfast!” the students reply, and then we run in place like we have a lot of energy but then soon run low on energy. “It’s about noon and I’m feeling low on energy—what can I do?” “Eat lunch!” We then pretend to be running and full of energy, and then it’s around six o’clock and we’re low on energy again and it’s time for dinner—to get more energy!

During this discussion, we develop a poster (Figure 2) showing a set of objects and what they get their energy from (e.g., a car and a pump at a gas station). At the end of the lesson, we use this chart as the basis for an “I Need My Energy” song (Figure 3). The song is then used as an engagement at the beginning of the next several lessons on energy.

Lesson Two: Lifting Energy

Key idea: Students discover that one way to give energy to an object is to lift it.

We start the lesson by reviewing the idea that energy allows an object to do something. For example, we discuss a car and what happens when it runs out of gasoline. Then we consider a ball sitting on the ground and ask students if they think the ball has any energy and to explain their reasons why or why not. Students generally respond, “It can’t do anything” or “It won’t move.” Then, we then lift the ball and ask if the ball has any energy now. Finally, we say, “If the ball doesn’t have energy when it’s on the floor but it has energy when in the air, how did we give it energy?” Students usually answer, “by lifting it.” We then introduce the term lifting energy. We show students a Hot Wheels track and car. When the car is at the bottom of a hill, it has to be lifted up the track in order for it to have energy to move along the track. We then ask students about their experiences bicycling up hills and coasting down them to connect lifting energy to their everyday experience.

Lesson Three: Spring Energy

Key idea: Students discover how spring energy can be stored in a flexible object.

In the next lesson, various toys and objects are used to show how one can store spring energy in a flexible object. We select one of the toys from the first activity, such as a pop-up toy, and ask students how it gets its energy—is it from us lifting it? (No, you squeeze it and then it “pops.”)

We then show a rubber band and ask the students how we can put energy into it (stretching it). This leads the students to the idea of stretching as well as squeezing. A rubber band–powered airplane is then used to show that they also put energy into the rubber band when it is twisted.

As in the first lesson, we are careful to distinguish how the object gets its energy and what it uses its energy to do.

Next, we use a kinesthetic activity to help the students internalize the idea that energy is stored when a spring is compressed: the whole class pretends to be springs and that something is pushing down on us, squeezing us, and giving us energy. We bend our knees to “squeeze down” and talk about how we are getting more and more energy, and then we suddenly release our energy by jumping up together. We then discuss how we get our energy (something squeezed us) and what we used our energy to do (jump).

We use the key words squeeze, stretch, and twist throughout the lesson, employing corresponding hand motions. The lesson concludes by teaching the students an energy cheer—“Lift, Squeeze, Stretch, and Twist”—to reinforce the key ideas from the last two lessons (Figure 4, page 23). This cheer is performed at the beginning of the subsequent lessons.

Lesson Four: Energy in Toys

Figure 5. Push 'N Go by Tomy.

Key idea: This lesson reinforces that many toys get their energy through “Squeeze, Stretch, and Twist.”

We disassemble several toys and show students the springs or rubber bands inside that are “squeezed,” “stretched,” or “twisted” to give the toy energy. Students should use goggles while the teachers are working with springs or rubber bands. When we run the lessons, the teacher does all of the disassembling of toys and working with anything we consider possibly hazardous (e.g., rubber bands).

Figure 6. PEZ dispenser.

While most wind-up toys use very small metal strips that coil when wound—and are hard to see and take apart—the Push ‘N Go by Tomy Toys has a large spring inside and is easy to disassemble and thus makes for an excellent demonstration (Figure 5). We ask students to predict what’s inside the toy and what happens inside when they push down on it. Then we disassemble while they watch—this only requires removing four screws and lends an air of suspense to the lessons—students have predicted that there’s a spring inside, and now they get to see if they were right.

Students also examine PEZ dispensers with holes drilled in them so they can see how the spring compresses when they open it (Figure 6). (The teacher drills the holes in the PEZ dispensers ahead of time with a standard electric drill.)

Figure 7. Rubber band pull- back truck.

In addition, we build our own pull-back truck; when the wheels are turned, the rubber band stretches, storing energy. Rubber bands are looped around the axle of a toy truck (Figure 7) and then attached to the hitch on the truck. When the truck is rolled backward, the axle turns, stretching the rubber band. When the truck is released, the rubber band contracts, pushing the car forward.

Lesson Five: More Springing and Lifting

Key idea: Students apply their developing understandings of spring energy to other common objects.

In this lesson, students examine more common objects that illustrate spring energy: slap bracelets, clipboards, and clothespins. A slap bracelet is at its lowest energy state when curled up—straightening (stretching) it adds energy to it. The clipboard and clothespin both have springs that are twisted when you open the clip on the clipboard or open the clothespin.

Figure 8. Paper clip hopper.

Then we make “paper clip hoppers” (Figure 8). To make a paper clip hopper: (1) bend the inner metal loop of a large paper clip at about a 30 degree angle from the outer loop, (2) tape a paper cover over the paper clip for safety and to allow students to decorate them, (3) push down gently on the hopper and release to make it hop. Students squeeze the paper clips, which stores energy in the toy, then watch them “hop.”

Assessments

To conclude our energy experiences, students bring in an object from home that illustrates “lift, squeeze, stretch, and twist” and then share with the class both how the object gets its energy and what it uses its energy to do. One student brought in a Boinks toy (www.boinks.com) that consists of a plastic mesh that acts as a spring. When the toy is squeezed and released, it jumps very far. Thus, the student was able to see how what she learned in the lessons related to other objects, even ones that did not look like springs. Students are assessed by the type of toy they bring in and their ability to articulate how it gets energy and what it uses its energy to do.

By the end of the explorations, students are usually confidently explaining to us how a wind-up toy gets its energy from a spring inside it and that the spring’s energy comes from twisting the spring, and we are confident that students are well on their way to understanding key energy concepts.

Stephen Van Hook (sjvanho@bgsu.edu) is an assistant professor in the Department of Physics and Astronomy at Bowling Green State University in Bowling Green, Ohio. Tracy Huziak-Clark (thuziak@bgsu.edu) is an assistant professor in the School of Teaching and Learning at Bowling Green State University.

Resources

Bradley, K.B., and P. Meisel. 2003. Energy makes things happen. New York: HarperCollins.
National Research Council (NRC). 1996. National science education standards. Washington, DC: National Academy Press.
Robertson, W.C. 2002. Stop faking it! Finally understanding science so you can teach it: Energy. Arlington, VA: NSTA Press.
Taylor, B.A.P. 1998. Exploring energy with toys: Complete lessons for grades 4–8. Middleton, OH: Terrific Science Press.

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