# Lesson Plan: Energy and How We Use It

In this unit, students will uncover how energy is converted to a variety of forms and how these forms are used in our homes from a power plant all the way down to charging our electronics.

 Author Grade Level Content Area Mrinda (Mindy) Thornlow High School (9 and 11) Earth Science and Physical Science

## Essential Questions

• List the 7 different types of energy and definitions of each type.
• Discuss how we can use more than one type of energy to fuel our lives and how they would work together.
• Discuss how we can use more than one type of energy to fuel our lives and how they would work together.
• What is energy?
• How do we know that things have energy?
• What happens to the energy in a system – where does this energy come from, how is it transferred within the system, and where does it ultimately go?
• How can energy be transferred from one material to another?
• What can be concluded about the total amount of energy in a system?

## Time Needed

• Prep time for the lessons that will be incorporated in this unit is 1 day.
• Time needed for students to get the lesson and culminate the end project is 5 school days.
• Wrap up time is 1 day which includes the quiz for the unit as well as going over the student work

## Standards

PSc.3.1.2 Explain the law of conservation of energy in a mechanical system in terms of kinetic energy, potential energy and heat.

EEn.2.8.1

• Critique the benefits, costs and environmental impact of various alternative sources of energy for North Carolina (solar, wind, biofuels, nuclear fusion, fuel cells, wave power, geothermal).
• Evaluate which sources of alternative energy may work best in different parts of the state and why.
• Extension: Examine for region, country, continent, hemisphere, and world.

## Making Connections

Prior to this lesson, we have covered a description of motion in terms of speed, velocity, and acceleration. Then, we moved into causes of motions in terms of forces, pushes/pulls, mass versus weight, gravity, momentum and circular motion. Once we covered these concepts, we moved into energy and how energy is related to the power that serves our homes and businesses.  Students also know that there is a transformation of energy types when we look at fun things like roller coasters, how energy is transformed into other forms, and how it relates to forces.

## Background

1. View energy interactions in terms of transfer and storage.
1. Develop the concept of relationship among kinetic (Ek), gravitational potential (Eg), elastic potential (Eel) & internal energies, such as nuclear energy (Enu), thermal energy (Eth) and chemical (Ech), as modes of energy storage.
2. System schemas are used to represent the relationship between energy transfer and storage which we will use in analyzing the power bills of the students and showing the transformations of energy types.
3. Emphasis on pie chart showing present energy storage.
4. Apply conservation of energy to mechanical systems such as those used to get power to homes and businesses.
2. Identify working, heating and radiating as energy transfer mechanisms.
1. Working is the transfer of energy into or out of a system by means of an external force.

## Materials

• Long cord with bob attached (simple pendulum)
• Wind-up toy
• Large play ball (ex. Basketball, volleyball, etc.)
• Small play ball (ex. Tennis ball, small bouncy ball, etc.)
• 2 large steel balls (Educational Innovations
• Pull back car
• Windup Toy
• Tuning fork
• Dropper popper
• Shake lights
• Students bring a copy of a power bill from home
• Data Sheet
• Chromebooks
• Paper templates for roller coaster making
• Yeast
• Water
• Epsom Salt

## Activity: Part 1 - Pre-Discussion

Note: This activity was modified from the Modeling Institute at NC State and the Arizona State University Modeling Institute.

Begin by identifying the location of the stations in the classroom. Tell students to follow the instructions at each station, carefully observing the phenomena. For each station, students describe their observations of the phenomena at the beginning, the middle, and the end of the activity.  For each observation, identify who or what can cause change. E.g. What is happening in the items to cause the change in a pull back toy? What did you do to make the items work?

Remind students that we have been studying change. We have also looked at force as a cause of change of motion. We will continue to look at change, but not necessarily in motion. Around the room, there are stations set up and we want to focus on who or what stores the ability to cause change in each of these situations.

## Activity: Part 2 - Energy Stations (Instructions)

• Wind Up toy: Please wind the toy. Be gentle. It only takes a few twists. Place the toy on the tabletop and release it. Make observations.
• Tuning Fork: Carefully strike the tuning fork with the mallet. Hold a pencil between the tines and observe.
• Rubbing Hands: With your palms together, compress your palms and fingers. Rub your hands, alternating up and down for several seconds. Place your hands on your cheeks. Make observations.
• Pull Back Car: Place the toy on the floor. Please wind the toy by gently pressing down on the toy and rolling it backwards just a few centimeters and releasing it. Make observations.
• Pendulum: Pull the bob up to your nose with the string taut (tight). Release the ball, allowing it to swing smoothly away from your nose (Note is very important to “let go” the bob and NOT to push the bob in any way.) Stand still as the bob swings away from you and then back towards you. Please do NOT move. Make observations.
• Dropper Popper:  Invert the Dropper Popper. Hold above the table or floor about 3 feet and release with the flat side down.  Make observations.
• Bouncy Balls:  Drop the ball from chest height. Observe multiple bounces. Drop the ball from above your head. Observe multiple bounces.

## Activity: Part 3 - Post-Activities discussion

• Have student groups whiteboard their station results, including their storyboards and who/what is storing the ability to cause change (energy).
• Focus the discussion on the idea that objects, such as people, springs, moving cars, etc, can store this ability to cause change.
• Once results are shared, establish a consensus concerning the ability to cause change being stored in objects.
• Choose a station (pull back car) and lead students through the development of a system schema paying close attention to the system (i.e., multiple objects – car, table, and person).

## Wrap Up and Action

Before beginning Exercise 1 of the Assessment, you will want to actually define these energy storage mechanisms/locations using more specific vocabulary words. Those include:

1. Gravitational Energy (Eg or GPE) – Energy stored in the combination of the earth/object interaction due to the object’s position. Higher positions and greater masses have more stored gravitational energy.
2. Kinetic Energy (Ek or KE) – Energy stored in the motion of objects. Higher speeds and higher masses have more stored kinetic energy.
3. Elastic Energy (Eel) – Energy stored in a stretched or compressed spring or other springlike material i.e. the popper. The material needs to be able to return to its original state on its own.
4. Chemical Energy (Ech) – Energy stored in chemical bonds within a substance.
5. Sound Energy (Esd) – Energy stored in sound and vibrations.
6. Nuclear Energy (Enu) – Energy stored in the nucleus of atoms.
7. Thermal Energy (Eth or TE) – Energy stored internally in objects associated with a temperature change due to friction or a collision. Students will often struggle with thermal energy because we can often not observe temperature changes when thermal energy is present. One way to demonstrate that to students is as follows. Use yeast and warm water in the stations to show how the water went from warm to the touch to “hotter” and then use Epsom salt with water to show the water going from tap temperature to a “cooler” temperature.

## Teacher Tips

The following provides steps for helping students consider how energy travels from their energy provider into their homes. Students can discuss ways that we can save on energy usage.

1. Ask students to obtain a copy of their home’s power bills that shows 12 months worth of consumption. Or ask them to research average power bills for homes in their communities. Using dimensional analysis students will convert kW/hour to watts on a conversion calculator.
2. Students will then conduct a home audit and make a list of all the appliances and devices that use electricity inside and outside of the home.
3. Student will then calculate how much electricity each device consumes by either reading the energy labels on the device itself or Googling the manufacturer’s information.
4. Once they had this information, they will estimate how many times a day they used each item and for how long. They may need help from their parents to answer this question. Students may also need the teachers’ assistance in calculating fractions. Calculations can be made on notebook paper.
5. Next students will be asked to calculate the wattage used by every light bulb in their home. Ask students to count each light bulb and write down the type of each bulb. Alternatively, you can ask students to take picture of each bulb type and note how many of each there are in the home. The teacher can walk students through the calculations together.
6. Now that we have all this information, the students added up their calculations and compared what their home’s average electricity usage was to see how close they were.  Here is where the conversation really got interesting because a lot of them realized that the average electricity wattage on their power bill was off from what they calculated in class.  We talked about how this happens and what electric companies and cooperatives call phantom loads (another term I had learned was “electric vampires”).
7. Using all the information they have gathered, students will sum their calculations and compare their home’s average usage to the actual bill or the community average. If the figure they calculated in class is different than the actual bill or community average, teachers can discuss why and what electric companies call phantom loads.
8. Students can then research how energy travels from the power plant to their homes. Students can create a flowchart to show changes in voltage from the power plant to the home to an electronic device of their choice.

Note: I used what I learned from my electric cooperative experience to discuss how the energy coming from the power lines is not the same as the energy that flows into our homes and why that is.

My name is Mindy Thornlow and I became an educator through a nontraditional route. After graduating from high school, I joined the U.S. Navy where I tracked the ice edge in the Northern and Southern Hemispheres for weather briefs used by pilots. Following my Naval career, I attended community college and earned an associate’s degree in science. I later earned a B.S. from East Carolina University with a concentration in Marine Biology. I worked in the private sector for a while, but felt I was missing something so I became a lateral entry teacher. I returned to East Carolina University to earn a masters in teaching.

I have completed 16 years of teaching, 15 of which have been at Trinity High School in Randolph County. I am a 2022-23 Kenan Fellow and completed my internship with the Randolph Electric Members Cooperative (REMC) and North Carolina’s Electric Cooperatives.