Science 6

Core Unit: Energy in Our Lives

Unit overview

How important is energy in our lives? How does energy have an impact on what we do, and on what information we receive? Thinking, walking, listening - all require an energy expenditure. Energy brings us information about everything around us - light energy enables vision, sound energy vibrates our eardrums, and electrical energy can be used to create sound and light.

In this unit, students will have an opportunity to examine the forms of energy that they think are most important to them in their lives, focus on three of the forms, and to discuss their dependence on energy. What is the nature of energy? How are the different forms related? How are they different? How does each behave? How is each generated? This unit is the third in a sequence of six core units in grades 4, 5, 6, 7, 8 and 9 that examine various aspects of energy.

Science writing and reading activities, as discussed in this Guide, should be incorporated into each lesson. Writing in learning logs, reading from newspapers and using those articles as models for reporting on the activities of science class, as well as writing editorials which express viewpoints on topics of interest with respect to the energy and energy use are three strategies through which students may refine their understanding of the concepts of science and develop their ability to communicate through the written word.

Science challenge, as described in this Guide, is meant to extend students' critical and creative thinking abilities in the context of the science concepts being studied. Activities involving science challenge should be incorporated into science lessons in each unit. The challenge is intended to give each student a chance to investigate an area of interest in more depth than would be possible for all students in a class to do. Science challenge is a key strategy for bringing the Adaptive Dimension to the classroom, and for encouraging independent learning.

Factors of scientific literacy that should be emphasized

Concept development

Foundational and learning objectives for Science and
the Common Essential Learnings

Investigate the forms of energy.
1. Identify various forms of energy.
2. Compare and contrast forms of energy.
3. Demonstrate how we recognize the presence of energy in a system.
4. Examine conversions of energy between forms.
5. Assess the efficiencies of conversions of forms of energy.
Consider how light, sound, and electrical energy have an impact on our lives.
1. Investigate how these forms of energy are formed and transmitted.
2. Recognize how individuals use and depend on these forms of energy.
3. Prioritize energy use in our lives.
4. Examine and consider low energy use lifestyles.
5. Explore the role of society in encouraging and enabling low energy lifestyles.
Develop a contemporary view of technology. (TL)
1. Examine their experience with technologies involving light, sound, and electricity.
2. Understand the social and cultural forces which underlay technological developments.
3. Appreciate how technological developments affect culture and society.
Understanding how knowledge is created, evaluated, refined and changed within science. (CCT)
1. Make careful observations during activities and discuss observations with others.
2. Strengthen perceptual abilities through concrete experiences.
3. Understand how knowledge is created and evaluated in science.

Suggested activities

Note: Many of the resources listed in Science: An Information Bulletin for the Middle Level - Key Resource Correlations describe activities or ideas for activities.

Which form of energy is most important to our lives: light, sound, or electricity? Which is second most important? Pick one of them and visualize a life without that form of energy? How would you adapt to survive? What other forms of energy or what changes in behaviour would help you accommodate the loss of use of the form you have chosen?

Write a short story that describes the ideas you have about how your life, and life in general, would change without that form of energy.

Factors: A3, B13, C6, D3, G6
Objectives: 1.2, 2.2, 2.3, 3.1
Assessment Techniques: peer-assessment, portfolios, homework
Instructional Methods: reflective discussion, focused imaging
Brainstorm to produce a list of all uses of all types of light. Categorize these according to essential to life and nonessential. Ask each group to choose one use that has been identified as essential. What type of adaptations would be necessary to permit life to proceed in the absence of light?

If each group has a different use, ask them to present their ideas orally to the whole class. An alternative way to present their ideas might be to create a story describing life that has adapted to no light or draw a mural depicting such adaptations.

Factors: B10, C6, E4, G1
Objectives: 2.3, 3.1
Assessment Techniques: self-evaluation, written assignments, presentations
Instructional Methods: concept formation, discussion
Carefully remove the glass from an incandescent light bulb. Is the filament still completely or partially intact? If it is completely absent find out where it goes by inspecting a new clear glass bulb. Trace the path of electricity in the bulb. What are the uses of the structures that aren't part of the circuit in the bulb? How does a light bulb produce light? Draw a diagram of a light bulb.

Factors: B10, C6, D1, G1, G3
Objectives: 1.4, 1.5, 3.1, 4.2
Assessment Techniques: performance assessment, short answer test items
Instructional Method: inquiry
Find out how light is produced in a fluorescent tube. Compare this method to how light is produced in an incandescent bulb. What are the advantages of each type of light production? Are there other ways in which light can be produced? How many ways of producing light can you discover?
How do the aurora borealis produce light? Is the light reflected light or light that is created in the sky? Is there a corresponding effect in the southern sky? Some people say that the northern lights make noise when they are especially bright. If you have heard the noise, describe it. Or find someone who has heard the noise and ask that person to describe it. In what way might the noise be generated? Is there any way we could use the energy of the northern lights? In what ways might the same process that produces them be useful to us?
How does a flashlight work? Obtain some flashlights and ask the students to take them apart to determine how they work. Ask them to draw a diagram of the path electricity would take through the flashlight, and then write a story pretending they are an electron in one of the dry cells, getting ready to embark on the voyage through the bulb and back to the cell.
How does a toaster work? Obtain some old non-working toasters and ask the students to take them apart to determine how they work. It would be a good idea to cut the electric cord about 2 cm from where it enters the toaster so that no one is tempted to plug it in. Ask them to draw a diagram of the path electricity would take through the toaster, and then write a story pretending they are an electron in the house circuits which encounters the plug of a toaster. What adventures would the electron encounter going through the toaster?

Repeat this activity with other small appliances, but not with old television sets. The coil in a television set may be charged with up to 25 000 volts.
Modify a flashlight to produce a narrow beam by making from poster board a mask with a small hole or narrow slot to tape over the reflector. Investigate the characteristics of the beam at various distances from the flashlight. Arrange six mirrors so that the beam bounces off each of them to hit a target. Draw a diagram of the path the beam takes as it hits the mirrors. What is the effect of taking one mirror out of the path?
List as many devices as possible which use mirrors as essential components. Draw diagrams to show how mirrors are used in each case, and build models of the devices if that is practical.
Convert a flashlight to produce a star-shaped beam. What design gives a star with the best definition (sharpest edges)?
A converging mirror can be used to reflect light to create an image on a card held between the object and the mirror. Experiment with images formed in and by converging mirrors? What characteristics do the images have? In what devices are converging mirrors used?

See if the same type of image formation is possible with a diverging mirror. (These are the mirrors that say on them: "Warning! Objects may be closer than they appear.")
Observe a speaker cone when a recording or the radio is playing. Design and build a vibration detector to amplify or enhance the vibrations you can see.
Use a balloon inflated to its limit as a vibration detector in front of large speakers. How sensitive are the balloon-detectors? How do distance, amount of inflation, size, colour, shape, thickness of walls, and other factors you can identify affect the performance of the balloon as a vibration detector?
If you put a string on the balloon, will the vibrations cause the string to vibrate? What type of sound (rock, classical, jazz) or instrument (clarinet, tuba, piano) cause the most or best vibrations?
Cut both ends from a large (1.3 litre) juice can. Cut the palm from a latex glove and stretch it over one end of the can. Fasten it in place with a heavy elastic band. Use silicone to attach a small (approximately 1 cm square) piece of a mirror to the centre of the latex across the end of the can. Shine a beam of light on the mirror so that it reflects onto a wall or screen. Sing a single note into the end of the can. Observe the reflected light on the wall. Talk into the can. Sing a phrase consisting of several notes. What effect does each have?
Cover a record turntable with foil. Set the speed of the turntable to 78 rpm. Gently touch the surface of the foil with one tine of a vibrating tuning fork. Stop the turntable and examine the pattern on the foil. What causes the pattern that appears? How could this method be used to estimate the frequency of a tuning fork? What improvements can you make to this vibration detector?
Build a record player with a needle and drinking cone (Sno-Kone) or other stiff paper cone. Use a magnifying glass or a stereo microscope to look at record grooves. A supply of records for this use can be obtained relatively cheaply from garage sales or record store clearance bins. Put the record on a turntable and place the pin in the groove. Turn on the player and adjust the pressure on the cone and pin so that sound is reproduced.

How do the grooves, pin, and cone each contribute to the production of sound? Why don't you have to move the pin (or the needle of a regular pick-up) from track to track on the record to play the whole record?
Play a record at different speeds. How does spinning the record faster affect the speed of vibration of the needle? What is the effect on the sound of changing the rate of vibration?
How do our vocal cords produce sound? When we whistle how is the sound produced? How does holding a blade of grass flat between the two thumbs cause a sound when one blows into the gap between the thumbs? Do birds have vocal cords to produce their sounds? When an object is going very quickly through the air, why does it make a whistling sound?
How does a dry cell produce electricity? Why do dry cells run down? If two or more cells are hooked together, the result is a battery. Most flashlights take two cells to form their battery. How many cells are there in a car battery? What produces the electricity in a car battery? How does an alternator or a generator in a vehicle produce electricity? How do rechargeable cells and batteries get recharged?
How is electricity produced at Boundary Dam? How is it produced at Coteau Creek and at Island Falls? Compare the processes used.
What effects on the body does an electrical shock have? Why do paramedics use electric shock to restart a stopped heartbeat? How does a pacemaker work? Does a healthy heart generate electrical impulses on its own?
What is the sound barrier? Why was it difficult to design planes that would "break the sound barrier"? What is a sonic boom? Why are the Concorde SST and all military aircraft prohibited from flying faster than the speed of sound at low altitudes? Present these questions for a brainstorming session or fact- finding period to generate questions for students to research.
How fast does sound travel? How fast is this compared to the speed of light? Here is an old method of determining the distance to a lightning strike. Count the seconds between the flash and the thunder, and divide this number by three. The result will give you the number of kilometres from you to the lightning. How does this method work?
Analogy for a sonic boom: Until the 1960's, trains had special cars that were used for sorting and transporting mail. There were people whose job it was to ride in that car and sort the mail. When the train would stop at a town, a postal worker would bring to the train the mail which had been posted at the post office since the last train was through town and then pick up a bag for that town. The outgoing bag would be loaded into the mail car and the clerks who worked in the car would sort the mail into the appropriate destination bags while the train was travelling to its next stop. At the next stop the same thing would be repeated. Individuals could also mail postcards or letters by putting them through a slot in the wall of the car.

Suppose that in 1947 a boy was riding the transcontinental train from Montreal home to Biggar. He decided to send postcards from various places across Canada to his mother who worked at the post office in Biggar. At Ottawa he got off the train, walked along the train to the mail car and put a postcard of the Parliament Buildings into the slot in the mail car. Then he got back on the train and rode to North Bay. There he got off and mailed a postcard of Lake Nipissing at the mail car. He repeated this at Capreol, Hornepayne, Longlac, Armstrong, Minaki, Winnipeg, Carberry, Melville, and Saskatoon. When he got to Biggar, his mother was at the train to meet him and pick up the mail. Among other things, what was in the mail bag his mother picked up at the train?

Application: Close your eyes and imagine how much sound a jet makes. The sound it makes travels at about 300 metres per second. If a jet is 1 500 metres away from you, how long will it take the sound to get to you?

Now suppose that the jet that is 1 500 metres away from you is coming toward you at 300 metres per second. How long will it take the jet to get to you? How does this compare to the time it will take the sound to get to you? The jet is travelling at the speed of sound, called Mach 1. The jet is like the person on the train. The sound is like the postcards. How is the air like the train?
Imagine that sound travels through the air in bundles. Are any of the bundles of sound from the last five seconds going to get to you before the jet does? When is the sound going to get to you? How much sound does a jet make in five seconds? What would this sound like if the whole five seconds worth of sound got there all at once?

Word Find Puzzle