Grade 4 Science
Core Unit: Forms of Energy

Unit overview:

The concept of energy is difficult for some students. Various forms of energy, and how they can be converted from one form to another, are investigated in this unit. Other related ideas, such as sources and uses of energy, are explored.

Related units:

In grade 1 the Core Unit on Motion provides an understanding of how things move. Understanding concepts related to force and energy develop this theme.

The Optional Unit on Simple Machines in grade 3 is closely related. Energy is required in order to do work.

The grade 4 Optional Units on Light and Electricity and Magnetism expand students' understanding of two kinds of energy. In a less direct way, because energy from the Sun is ultimately responsible for the weather patterns on Earth, the Core Unit on Predicting Weather can be related to the study of energy. The grade 4 Core Unit, Forms of Energy is essential in preparation for the following grade. The grade 5 Core Unit on Resources, furthers students' understanding of the sources of energy, from an environmental perspective. The Core Unit on Heat, and the Optional Unit on Force, Motion and Work, require an understanding of energy.

In grade 6 the Unit Energy in Our Lives involves energy.

Suggested themes:

electricity, energy, forces, forms of energy, heat, light, machines, matter and energy, motion, sound, sources of energy

Factors of scientific literacy which should be emphasized:

Common Essential Learnings foundational objectives which should be emphasized:

To promote both intuitive, imaginative thought and the ability to evaluate ideas, processes, experiences and objects in meaningful contexts. (CCT)
To strengthen students' understanding of energy through applying knowledge of numbers and their interrelationships. (NUM)
To develop an understanding of how knowledge is created, evaluated, refined and changed within science. (CCT)

Science foundational and learning objectives:

Identify energy in its various forms.
1. Identify common forms of energy.
2. Distinguish between kinetic energy and potential energy.
3. Show relationships between force and motion.
4. Investigate the phenomenon of friction.
Explain energy conversions and energy losses.
1. Give examples of conversions of energy from one form to another.
2. Explain the loss of energy in any energy conversion.
3. Explore the production and use of common forms of energy.

Suggested Activities:

Have groups work in groups to determine the effect that the position of the fulcrum has on the force needed to balance a load in a first class lever. (In a first class lever the fulcrum is positioned between the load and the applied force.) Use small, plastic rulers to make the levers. Wooden pencils can be used as the fulcrum. Tape some small medicine cups or coffee creamer cups at either end of the ruler. They serve to hold objects, rather than trying to balance them on the lever.
The grade 3 Science Core Unit: Properties of Matter, activity #1 describes how this is set up. Use the second method.
Paper clips or washers can be used as weights. The amount of applied force needed to balance some other object at the load end of the fulcrum is expressed in washers or paper clips needed at the other end. Once this has been determined, record the results and move the fulcrum to a different position, keeping the fulcrum between the load and the applied force. Repeat several times. Have students analyze the information to develop a generalization regarding the relationship between the position of the fulcrum and the amount of force needed to counteract the load. Some students may discover the law of the lever. However, a mathematical treatment of levers is not necessary at this grade level.
Relate this activity to how levers are used around the home. Have students bring in a few simple machines which illustrate the use of levers. A teeter totter in the school playground is one use of a first class lever which some students may mention. Have both boys and girls participate actively in any activities on levers.
Factors: A4, B7, B8, B9, B10, B11, C5, C6, C7, C11, C12, D1, E7, G1
Objectives: 1.3, 2.3
Assessment Techniques: 1, 3, 4, 5, 8, 9
Common Essential Learnings: Critical and Creative Thinking, Technological Literacy. This activity involves collecting and analyzing information. By performing an activity involving levers, and relating it to familiar experiences, students begin to examine relationships between science and technology. They develop an appreciation of the fact that machines make it easier to do work.
Have one student push on a desk. Does the desk move? Why? Have the same student push with about the same force on a chair. What is the result? Why? Use the same force to push on a wall. What happens? Why?
Factors: A4, B7, B9, B10, B11, C3, C6, C9, C10, G1
Objectives: 1.3, 1.4, 2.1, 2.3
Assessment Techniques: 1, 3, 5
Common Essential Learnings: Critical and Creative Thinking. By making careful observations in controlled situations, students begin to question certain events and phenomena. They develop their ability to reason. Their perceptual abilities improve. They focus their attention on cause-effect relationships, stimulating intellectual activity.
Each student can hook their two index fingers together and pull. Is a force being exerted? Is there motion occurring? Can the students explain what they observe. (A force is needed to initiate motion, but not all applied forces result in motion. Furthermore, not all motion needs the constant application of a force. Forces of equal magnitude acting in opposite directions cancel one another, resulting in no net force, and hence, no motion.)
This is an activity which is used to motivate students for further investigation. It is quick and simple to do. Effective science teaching does not have to involve elaborate, expensive equipment. Many quick demonstrations and activities need no equipment or can be done with only a few simple, readily available things.
Factors: A4, B7, B10, C3, C6, E7, G1
Objectives: 1.3, 2.3
Assessment Techniques: 1, 3, 5
Common Essential Learnings: Critical and Creative Thinking. This leads to some interesting rules and generalizations regarding Newton's laws of motion.
Generalizations can be helpful starting points, but students should try to think of exceptions, since often a generalization results in oversimplification.
Have a student balance on a skateboard. It would be a good idea for the student to wear a helmet and elbow pads. Give the student a basketball and have the student throw a two-handed chest pass either forward or backward from the board. Observe what happens. Then have the student throw a pass sideways from the board. Give the student a beach ball and repeat the procedure.
If two skate boards are available, place them end to end with one student on each skateboard, facing each other. Have them push off each other. Which way do they go? Does it make any difference which one does the pushing?
It is too complex a concept to explain to students how momentum is being conserved in these situations. It is more important to enable students to think about the problem rather than to place any emphasis on obtaining a "correct" answer.
Factors: A4, B7, B9, B10, B11, B13, C3, C6, C8, C9, C12, G1
Objectives: 1.3, 2.1, 2.3
Assessment Techniques: 1, 3, 5
Common Essential Learnings: Critical and Creative Thinking. Through careful observation and directed inquiry, students can be encouraged to wonder how force is being used to cause the motion of the skateboard(s). They may begin to speculate on where the energy used to produce the force comes from.
Real problems are often very complex and answers to many of the questions raised by science are not known. It is the process of inquiry which, perhaps more than anything else, makes science a unique way of knowing.
Anchor a piece of fishing line to a desk at the front of the classroom, about 1 m from the floor. Thread a plastic straw onto the line. Tighten the line and attach it at the back of the room. The line should be taut. Move the plastic straw to one end of the fish line. Blow up a long, thin balloon and hold the opening. Have someone tape the balloon to the straw with two pieces of masking tape so that the long axis of the balloon points in the same direction as the fishing line and the opening of the balloon is closest to the wall. Release the opening so the air rushes out.
Factors: A4, B7, B10, B11, B13, C3, D1, G1
Objectives: 1.3, 2.1, 2.3
Assessment Techniques: 1, 3, 5, 8
Common Essential Learnings: Technological Literacy. The activity illustrates the action-reaction principle. The air rushing out of the opening of the balloon causes the straw to move in the opposite direction. The jet plane and hydroplane could not have been developed without an understanding of this principle and of the laws and forces which govern motion.
Bend a paper clip to make a stand which will support a shelled peanut, walnut, or cashew about 2 or 3 cm above the table top. Place a nut (shelled) on the stand and ignite. How long does it burn? Where does the heat come from? (A sugar lump can also be burned on an apparatus like this. If you rub some cigarette ashes or some fine paper ashes on the surface of the cube, it will light more easily.)
Stored chemical energy is being converted into heat. This is the energy in foods that determines their caloric content.
This activity enables students to think about what forms of energy are involved in this transformation. Some might also make the connection that the energy that animals have is due to chemical changes occuring following the ingestion of food.
This provides a suitable opportunity to integrate ideas related to health and nutrition and how the body converts food into energy.
Factors: A4, B9, B10, B13, C3, C5, C6, C8, E7, G1
Objectives: 1.1, 2.1, 2.3
Assessment Techniques: 1, 3, 5, 7c
Attach a C-clamp to the edge of a table and suspend a pendulum from it, so that the bob is slightly above the floor at its lowest point. Alternatively, attach a string to a ruler, and tape the ruler to the table. On the floor, directly below the rest position of the pendulum, place a small block of wood. Pull the pendulum back and release it, allowing it to strike the wood. Measure the height of the bob above the ground when the pendulum bob was swung back, and how far along the floor the block of wood moved. Do several trials, varying the displacement of the pendulum bob for each trial, returning the block of wood to below the rest position before each test. Predict where the block of wood will stop before each trial is conducted. Measure the actual position.
Compare the predicted position and the actual one. Tabulate the results. Analyze the results. See if a relationship can be developed between the distance the block moved along the floor and the amplitude of the pendulum's swing.
To develop an understanding of the effect of friction, use wax on the bottom of the block and repeat the tests. Tape some sandpaper to the bottom of the block and repeat a third time. Compare the results to conclude what effect the surface of the block has on the distance that it moves.
Factors: A4, B7, B8, B9, B10, C2, C3, C5, C6, C7, C9, C11, C12, E7, G1
Objectives: 1.2, 1.3, 1.4, 2.1, 2.3
Assessment Techniques: 1, 3, 5, 7, 8, 9
Common Essential Learnings: Numeracy. In this activity, students collect quantitative data. Measuring, predicting and tabulating provide the basis for analysis of experimental results. If a relationship exists between the displacement of the pendulum bob and the distance along the floor that the block of wood moved, then the numerical data analysis can help reveal it.
Integrate this activity with skills that students are developing in Mathematics.
Place a thermometer in a jar. Seal the lid and put the jar in a sunny place. Put a second thermometer beside the jar. Predict what will happen. Record the temperatures on the two thermometers every five minutes for thirty minutes. Summarize the results in a table. How do the temperature readings inside and outside the jar compare? What are the implications of this activity to deciding where to place a thermometer?
Use this activity as an analogy of how a greenhouse works. It could be extended to introduce the idea of the Greenhouse Effect.
Factors: A4, B8, B9, B10, B11, C2, C3, C5, C7, C9, C10, C11, C12, D1, E7, G1
Objectives: 1.1, 2.1, 2.3
Assessment Techniques: 1, 3, 5
Common Essential Learnings: Numeracy, Technological Literacy. The main focus of the activity is on the collection and analysis of quantitative data. The activity also illustrates greenhouses and the Greenhouse Effect. Light enters the jar, is partially absorbed, and converted into radiant heat energy. The heat energy is trapped inside.
Give students metal paper clips. Have them open up one of the paper clips and bend the metal back and forth in the same place many times. Do they notice that heat is produced. (Some types of paper clips may work better than others in this activity. If no suitable paper clips can be found, try using coat hanger wire or old telephone wire that has had the insulation removed.)
Ask students why people rub their hands together on a cold day to keep them warm. Can they think of other ways that friction produces heat.
To further reinforce this concept, demonstrate the following phenomenon. Pour cold water into a mixing bowl. Measure the temperature of the water. Using an egg beater, quickly beat the water for about two or three minutes. Measure the new temperature of the water. Are students able to transfer their knowledge of what happened in the previous activities to this one. In all of the instances, friction is producing heat.
Factors: A4, B7, B8, B10, B13, C2, C3, C5, C9, E7, G1
Objectives: 1.3, 1.4, 2.3
Assessment Techniques: 1, 3, 5
Common Essential Learnings: Critical and Creative Thinking. Friction can result in the production of heat, as this activity serves to illustrate. Kinetic energy is being converted into heat. Why does the paper clip break if one continues to bend it in the same place many times? A few of the students might be able to develop a hypothesis which accounts for this. However, most students would not have had sufficient exposure to the idea of the structure of matter to be able to do this.
Have students make a string phone. For each group, use two metal cans or paper cups, about 6 m of string, and two paper clips. Poke a hole in the middle of each can or cup. Thread the string through the hole. Tie the string to the paper clip to keep the string from being pulled back through the hole.
Stretch the string between each phone and have students talk to one another. To "tap" a phone, cross two sets of strings at right angles. Tie them together where they intersect. Have two students continue a conversation and another two students listen in on the conversation through the tap.
As a follow-up activity, invite someone from the phone company to explain how telephones work.
Telephones, of course, do not work by sending sound vibrations along phone lines! Energy such as light, electricity, or microwaves is sent from one point to another, along fibre optic cables, copper wires, or from a transmitter to a satellite and back to a receiver on the Earth. The string phone does not involve an energy conversion. It does, however, illustrate that some forms of energy can travel from one place to another along a particular path, and that losses occur due to friction as the sound waves are propagated. These concepts should be developed instead of leaving students with the impression that the string phone shows how a telephone works.
How does the "tap" work? If students recognize that sound energy consists of vibrations in the form of waves, and that those waves travel through the string, they begin to appreciate that the vibrating string can cause the "tap" string to begin vibrating as well (due to mechanical resonance). The sound energy is dispersed, leading to an even fainter signal. (Refer to the notes in the following activity as well.)
Factors: A4, B7, B8, B10, B13, C2, C3, C9, E7, G1
Objectives: 1.1, 1.4, 2.2, 2.3
Assessment Techniques: 1, 3, 5, 7, 8
To each of two paper cups, attach about 30 cm of string by poking a hole through the bottom of the cup, threading the string through, and tying a paper clip to the end, much like in the previous activity. Take the free ends of each of the two strings and tie them to either end of a metal coat hanger.
Hold a cup to each ear, allowing the coat hanger to hang vertically. Tap the coat hanger lightly with a pencil. The sound will be heard by the person holding the cups.
Hold another coat hanger beside the first, with the cups from the first still at the ears. Tap the second coat hanger, and then the first. Is there a difference in the loudness of the two sounds heard by the person listening through the cups? Which sound reaches the ears better?
The path that the sound follows can be traced on a diagram. Encourage students to alter how they tap the coat hanger so that a different sound is heard in each of the paper cups, producing an effect similar to stereo.
Factors: B7, B10, B13, C3, C9, D1, E7, G1
Objectives: 1.1, 2.1, 2.2, 2.3
Assessment Techniques: 1, 3, 5, 8, 9
Common Essential Learnings: Technological Literacy, Communication. Unlike the previous activity, this more clearly illustrates a conversion of energy. Kinetic energy is transferred into sound when the pencil strikes the coat hanger. The vibration then travels from the metal coat hanger through the apparatus until the sound is heard.
As in the previous activity, it is misleading to suggest that this model illustrates how a particular technology works. Students might immediately suggest that the device resembles a set of stereo headphones. The only similarity is in the vibrating part of the headphone, but not in how the signal is transferred to the headphone. Models can be very useful, but sometimes misleading. They do not always work on the same principles as what they are trying to depict. Rather than trying to analyze how stereo headphones work, or how a telephone works (as in the previous activity), examine how technology has changed our lives. What have telephones and headphones done to help us? How have these devices shaped society? Undesirable problems have emerged (e.g., obscene phone calls, fraudulent telephone marketing, headphones which are too loud, causing partial deafness or blocking out important sounds warning of danger).
Mechanical energy can be converted into sound. This can be illustrated by making a moose call. Punch a hole in the bottom of a coffee can. Thread about 32 cm (or more) of cotton rope through the can, tying a large knot on it so that the rope does not pull all the way through the can.
Put a wet woollen sock over your hand. Hold the can securely with your uncovered hand and quickly slide the sock along the rope away from the can. Vary the sound of the moose call by changing the speed at which you pull the sock. Have students practice their moose calls outside. This can get very noisy inside.
Factors: A4, B7, B9, C2, C3, D1, E7, G1
Objectives: 1.4, 2.1, 2.3
Assessment Techniques: 1, 3, 5, 8
Common Essential Learnings: Technological Literacy. This is an excellent activity to show how people design things in order to help them fulfil their needs. Few people can imitate the sound of a moose without using a moose call. By using a moose call properly, a moose can be called out of the bush, making a successful hunt possible.
Place a Slinky (tm) on the top step of a stairway. Give it a slight push, observing it snake its way down the steps.
Discuss why it moves in that way. See if the students can decide where it gets the energy to move.
Factors: A4, B9, B13, C3, C6, E7, G1
Objectives: 1.1, 1.2, 1.3, 2.1
Assessment Techniques: 1, 3, 5, 7c, 8
Common Essential Learnings: Critical and Creative Thinking. Students can relate this experience to their understanding of energy conversions, using it as a way of illustrating how potential energy can be converted into kinetic energy.

Grade 4 Science Core Unit: Forms of Energy