Energy Transformed 1: How Energy Transfers
Lesson 3 of 13
Objective: SWBAT identify types of energy and ways in which energy transforms.
In this activity, students uncover their ideas on ways that energy can be transformed or converted from one form to another. You will push them to think about the processes used to convert energy, as well as think about ways in which energy loss may be occurring during conversions.
The key concepts in this lesson are:
- Energy can be neither created nor destroyed, but converted from one form to another. (First law of thermodynamics.)
- The two states of energy are potential and kinetic.
- Energy can be classified by its form or state.
- Energy comes in several forms including sound, chemical, radiant (light), electrical, nuclear, mechanical, thermal (heat).
- Flashlight (for demonstration)
- Student handouts
- List of forms of energy from earlier lesson
To focus students' attention and begin the thinking process about energy transfer, hold up a battery-operated flashlight. Turn the flashlight on and off. Ask students what forms of energy can they identify in the process of turning on a flashlight (radiant, chemical potential, electrical, mechanical, and thermal).
I don't worry that they can't name all of these at this point. Make/keep a list of their ideas and then at the end of this activity go back to the flashlight and show it to them again and see if they want to add or amend the list of forms of energy identified. They may need some help thinking about the energy that is required to activate the switch (mechanical) and they may need to think about the thermal energy generated both by the transfer of chemical energy from the battery and radiant energy from the light bulb.
Provide the students with the Energy Transfer handout and take them through identifying the energy transfers for the first few images. For instance, the television would be electrical to radiant (light), thermal (heat), and sound. Have them record their responses on the second page. Continue this for a few more examples until you feel the students get the hang of it, then have them work together to identify the rest of the energy transfers.
As the students are working, move around the room and check in with those students who may need support at this time. If they are struggling, have them refer back to the list of energy forms that you have posted from the prior lesson and talk them through the types of energy transfers that seem logical for each item.
Some of the items may have more energy transfers than are necessary to identify at this time. For instance the iPhone has many energy transfers that may not be obvious to most students. Some of the items they may or may be familiar with, such as the waterwheel or nuclear power plant.
Give them the support that they need to figure out at least one energy transfer for each item. The goal here is not to figure up all the energy transfers but at least to be thinking about how energy changes form. In a future lesson students will be asked to identify a more complete flow of energy transfer in a system.
To wrap up this lesson, ask for volunteers to share the types of energy transfers they identified. Depending on the size of your class, you could assign one energy transfer per student from this list, or have one table group identify four or five to the class. You might think about having the students come up to the board to present. I always like to look for opportunities for students to practice their speaking and listening skills.
As students are explaining their thoughts on energy transfers, pay attention to misconceptions and areas that you may need to focus on for upcoming lessons.
In the video below one of my students reflects on how this activity helped to push her thinking in this regard.
To connect this lesson to the students lives outside of the classroom, assign Illustrations of Energy and Transformations for homework.
Alternatively, or in addition, you could have students go home and identify five or six different energy transfers on their own and write about them. Either way I would be sure to review their ideas is of the next class.