Get Current on Energy

Engage: 

Begin the lesson by getting the student’s attention about energy by showing the video How to Save Energy for School Teaching at https://youtu.be/_WAWFEr9p30.

Explore:

1. As a class, have the students prepare a list of the 10 most needed uses of electricity at home. NOTE: These may include the stove, refrigerator, lights, heating, air conditioning, hot water heater, microwave, TV, alarm clock, washing machine, clothes dryer, hair dryer, computer, etc.

2. Discuss what life would be like without these 10 most needed uses of electricity. Are these items necessities or luxuries? Have the class make determinations based on their opinions. There are no right or wrong answers.

3. Have the class list other uses of electricity outside their home that are necessities. These may include traffic lights, hospital equipment, etc.

4. Discuss with the class that there is an alternative at home to just not using electricity and that the alternative is conserving electricity by using energy-efficient appliances and by using them wisely. Additionally, you can avoid using electricity by doing things such as hanging clothes to dry and opening windows instead of running the air conditioner.

5. Ask, “What are some examples of wasting electricity?” Review your top 10 list and how electricity can be wasted by improper use. For example, running the heat with windows open, leaving lights on when no one is home, leaving televisions on when you’re not watching and leaving the refrigerator door open.

Explain:

Have the students investigate ways to conserve energy at school.

1. Try to locate the areas of your classroom with the greatest heat/energy loss (during the heating season or the area of greatest cooling loss in the summer). Ask the students to predict where these areas might be. Write their predictions on the board. 

2. Place several thermometers around the classroom (e.g., by doors and windows, high in the class and low to the floor, next to an inside wall – but avoid putting a thermometer next to the heating/cooling register). Assign a team of students to take readings at various times during the day. (Every hour works well.)

3. Record their findings on the board by location and determine the following: • Where is the room warmest? • What is the coldest location? • Where do you think heat is moving out of the room? • What are your ideas for keeping heat in the room?

4. Discuss how insulation helps keep heat in the classroom. Insulation is any material that prevents the movement of heat.

5. Show the students the video What’s the Best Insulator? at https://youtu.be/l81M7Xhwzk0.

Elaborate:

Distribute copies of My Home Energy Conservation Checklist and discuss it with the class.

• What do the students think about these conservation methods?

• Which ones are the students already doing?

• Which ones do they think make a difference?

• Which ones do they think are too much trouble or too inconvenient?

Ask the students to select several of these conservation methods to discuss with their families. Use the My Home Energy Conservation Proposal form included with this lesson and have students fill out suggestions for their families. Encourage the students to take the list home.

Evaluate: 

EXPERIMENT 1

1. Tell the students that they are going to conduct an experiment in class testing different types of material for their insulation quality. Assign the students to bring in a piece of insulation material that they think will help to keep an ice cube from melting. This could be a scrap of cloth, plastic, paper, etc. Ask the students not to bring ThermosTM bottles or coolers.

2. For the experiment, give each student a copy of the Melt Down Student Worksheet to review.

a. Quickly give each student an ice cube in a paper cup and instruct students to wrap the cup and cube in their material quickly.

b. Have all students place their experiment cups in the same location. Remind them that the temperature in the room can vary and that this variation would effect the experiment results.

c. You will need to call out the start and check times so that all students are working on the same time line.

d. Allow the students to check their experiments and record results on their student sheets.

e. During the experiment, as students say their cube has melted, record on the board the type of insulation material and the time.

3. Ask the class, “Which ice cube lasted longest? What was the most effective insulation? What is the purpose of insulation?”

EXPERIMENT 2

In this activity, the students will discover how various materials conduct heat differently. Begin the experiment following these steps: 1. Place the three spoons (plastic, metal, wood) in a shallow glass dish with the handles at the bottom and the mouth of each spoon extending over the rim. Place the smaller glass dish on top of the spoon handles.

2. Put a small pat of butter in the mouth of each spoon.

3. Put a bead on each pat of butter.

4. Carefully pour hot boiling water into the smaller dish and let it overflow into the larger dish until it is almost completely full.

5. Set the timer and observe what happens to the butter and beads. Watch the experiment for 5-10 minutes to see what happens. Conclude the experiment by asking these questions: BEFORE THE EXPERIMENT: HYPOTHESIS

• Which bead fell off first? Why?

AFTER THE EXPERIMENT

• Which spoon’s butter is melting fastest? Why?

• How long did it take each spoon’s butter to melt?

• Which material conducts heat best – wood, plastic or metal?

The results should show that metal is a good conductor of heat, while wood and plastic are good insulators.

E-Learning Activity: 

HEAT TRANSFER VIRTUAL LAB

Learn about heat transfer and how to keep things warm by testing the characteristics of different materials with this fun activity for kids. Some materials are good thermal conductors, easily letting heat pass through them, while others are good thermal insulators, not easily letting heat pass through them.

Conduct experiments and watch how the temperature changes. Record your results on a table and make your own conclusions, some materials help keep things warm while others make them get cold quickly. Find out if metal, cardboard, and polystyrene are good at thermal insulation or have good thermal conductivity by checking out this heat transfer activity.

Visit www.sciencekids.co.nz/gamesactivities/ keepingwarm.html for more details.

Essential Learning: 

Background Information for Third Grade: 

This lesson encourages students to obtain information from different sources, including observations, informational texts, videos and more to identify and describe problems related to the transfer of heat energy, both in terms of facilitating/helping heat transfer and/or inhibiting/blocking heat transfer. For example:

• A student’s hot cocoa gets cold quickly when served in a paper cup;

• Students are burned while sliding down the metal slide at recess; and

• Classroom laptops are overheating and turning off during use by students.

The students should engage in the design process to create and test different solutions to solve the problem of heat transfer through insulating or conducting the transfer of thermal energy. This process should include asking questions about problems related to using insulators to inhibit heat transfer or using conductors to facilitate heat transfer. Applying an understanding of heat transfer, insulators and conductors, design a solution or device that include the following:

• Conductors of heat transfer facilitate or help the transfer of heat energy. Material that allows heat to move easily through them, and from one object to another through direct contact, are called conductors. Metal objects are good conductors of heat because heat can transfer easily through the metal. For example, the handle of a metal spoon will become warm when the spoon is placed in hot water; and

• Insulators of heat transfer inhibit or block the transfer of heat energy. Material that does not allow heat to move easily through them or from one object to another through direct contact are called insulators. Wooden and plastic objects are good insulators of heat because heat does not transfer easily through them. For example, the handle of a wooden or plastic spoon does not become warm when the spoon is placed in hot water. Testing their devices or solutions and collecting data is important to see how effective their solutions are at insulating or conducting heat transfer. They can analyze and interpret their data to determine if their solutions are successful in facilitating or inhibiting heat transfer. They also can use their data to refine and retest their designs (if necessary) and discuss their solutions. 

Background Information for Sixth Grade: 

The students should be encouraged to develop and use models to describe and compare how heat energy can transfer in the three ways (i.e., conduction, convection, radiation). Conduction is the transfer of thermal energy through direct contact. The transfer of energy as heat occurs between particles as they collide within a substance or between two objects in contact. All materials do not conduct heat energy equally. Poor conductors of heat are called insulators. For example, if a plastic spoon and a metal spoon are placed into a hot liquid, the handle of the metal spoon will get hot quicker than the handle of the plastic spoon because the heat is conducted through the metal spoon better than through the plastic spoon. The energy transfers from an area of higher temperature to an area of lower temperature.

By designing and testing devices, you can determine how various materials and/or combinations of materials affect how quickly heat transfers by conduction, convection or radiation 

• Conductors are materials that easily carry heat or electric current. Glass and metals are good conductors of heat. When a metal pan is placed on a heat source, it will quickly get hot and conduct the heat to whatever is inside of the pot.

• Insulators are materials that are poor carriers of heat or electric current. Wood and animal fat (blubber) are good insulators; they do not conduct heat very well. A polar bear swims in freezing water but the bear does not freeze to death as a human would. The bear’s thick layer of fat insulates the bear and traps heat inside of the bear’s body. Various materials – including but not limited to, water, metal, glass, wood, plastic, air and reflective and non-reflective substances – should be tested in order to determine how well each conducts heat by conduction, convection and/or radiation.

*Experiments listed under the 'Evaluate' section of the lesson plan*