Download Unit B Ch 6 TR

Chapter 6 Controlling Heat Transfer
Chapter Opener (p. 104)
Starting Point Activity: Survivor (p. 105)
6.1 Absorbing and Losing Heat (p. 106)
Conduct an Investigation 6–A: Keeping It Cool (p. 106)
Find Out Activity: Does Double the Water Take Double the Time to Boil? (p. 108)
Specific Heat Capacity (See Section 6.1)
Reading Check (p. 108)
Try This! (p. 109)
Warming Up and Cooling Down with Oceans
Did You Know? (p. 110)
Science Myths (p. 110)
Key Terms (p. 110)
Check Your Understanding (p. 110)
6.2 Keeping Heat at Home (p. 111)
Reading Check (p. 111)
R-value (See Section 6.2)
Conduct an Investigation 6–B: Ice Sculptures (p. 112)
Other Ways to Keep the Heat in Your House (See Section 6.2)
Find Out Activity: Will Aluminum Foil Keep You Warm? (p. 114)
Windows and Doors That Keep Heat In (See Section 6.2)
Reading Check (p. 115)
Did You Know? (p. 115)
Career Connect (p. 115)
Try This! (p. 115)
Think & Link Investigation 6–C: Energy Efficiency (p. 116)
Off the Wall (p. 116)
Controlling Heat Transfer (See Section 6.2)
Reading Check (p. 117)
Try This! (p. 117)
Design & Do Investigation 6–D: When You’re Hot ... (p. 118)
Kitchen and Workshop (See Section 6.2)
Reading Check (p. 119)
Key Terms (p. 119)
Check Your Understanding (p. 119)
6.3 Keeping Yourself Warm (p. 120)
Reading Check (p. 120)
Try This! (p. 120)
Reading Check (p. 120)
People of the North (See Section 6.3)
Reading Check (p. 121)
Did You Know? (p. 121)
Did You Know? (p. 121)
© 2002 McGraw-Hill Ryerson Limited
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Internet Connect (p. 121)
Design & Do Investigation 6–E: A Winter Survival Car Kit (p. 122)
Try This! (p. 122)
Internet Connect (p. 122)
Keeping Cool (See Section 6.3)
Reading Check (p. 123)
Find Out Activity: Is Heat Transfer a Black and White Issue? (p. 123)
Dressing for Intense Heat — or Cold (See Section 6.3)
Reading Check (p. 124)
Off the Wall (p. 124)
Did You Know? (p. 125)
Check Your Understanding (p. 125)
Chapter 6 Review (p. 126)
Pause & Reflect (p. 127)
Chapter at a Glance
Prepare Your Own Summary
Answers to Blackline Masters
© 2002 McGraw-Hill Ryerson Limited
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Chapter 6
Using the Chapter Opener (p. 104)
• Read the chapter opener with your class. The subject of fire-walking will likely spark student curiosity
and interest. Ask students if any of them has ever seen a fire-walking demonstration. You might wish
to show a video clip — the last episode of Survivor I and the film Ace Ventura: Pet Detective both
contain fire-walking scenes.
Brainstorm with the class what the secret of fire-walking might be. Guide students to consider
how it might be related to the chef’s method of testing the pan’s heat. (Fire-walking is possible
because moisture on the walker’s feet vaporizes. This evaporation both absorbs the heat that would
have otherwise scorched the feet and creates a vapour barrier between foot and fire. This effect is
called the “Leidenfrost Effect.”) Students will better understand this relationship after they have
completed this chapter.
For more information about fire-walking, go to www.mcgrawhill.ca/links/science.connect1,
then to Teacher Resources, Web Resources, Unit B, Chapter 6, Fire-walking.
• Have an electric frying pan ready and show students the chef’s method of testing for heat. Students
unfamiliar with the chef’s trick might know the similar test to see if an iron is hot; i.e., wetting a
finger and touching the surface quickly.
• Ask students to answer the Getting Ready questions in their Science Log. Remind them that they can
return to these questions throughout the chapter to add to or change their initial responses. Discourage
them from focussing solely on whether their answer is correct or incorrect; point out that revision
often indicates a change in one’s level of understanding.
• Have students read through What You Will Learn, Why It Is Important, and Skills You Will Use to
give them an idea of the direction this chapter will take. Explain that they will be applying and
building on what they learned in Chapter 5.
Meeting Individual Needs
LD Learners/Persons with Physical Disability(ies) — To help the students with tests in this chapter,
read the questions and capture them into an audio file on your computer. Place the audio clip right in
the electronic test file and press it on to an exam (text and audio) CD-ROM. Allow students with
disabilities that involve reading to use a computer during the exam. They can click on the question
(audio button) and hear (using head phones) the teacher reading the question. Student can replay the
audio file as often as they need to.
Alternative Opening Activity
• {AB.Sc14.B.K.1.ii}{AB.Sc14.B.K.2.i}{AB.Sc14.B.S.3.iv}{AB.Sc14.B.S.1.iii}{AB.Sc14.B.S.2.iii}
{AB.Sc14.B.S.3.v}{AB.Sc14.B.S.3.vi}
Modify the activity by having students design footwear for cold conditions. (See the Extension
question in BLM 6–1, Planning to Survive.) In winter, the footwear can be tested on a bed of snow
instead of hot sand.
Starting Point Activity (p. 105)
Survivor
Purpose
• Students design and build heat-proof footwear.
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Advance Preparation
WHEN TO BEGIN
1–2 weeks before
3–4 days before
APPARATUS
• scissors or utility
knives
WHAT TO DO
• Check plant stores, greenhouses, and woodlots for large leaves and bark. (A nursery may
collect large dead leaves for you.)
• Gather materials.
• Collect large leaves as planned, or assemble a supply of corrugated cardboard and
construction paper.
• Get jungle music or a shipwreck video to set the scene.
MATERIALS
• old rags (that can be destroyed) brought in by students
• thick plastic bag or very heavy cloth or canvas that can be cut up (for duffel bag)
• aluminum foil
• 2 jugs (4 L) full of water
• old tree bark (or cardboard)
• large leaves (or construction paper)
• paper
• pencil
BLM 6–1, Planning to Survive
Time Required
• 60 minutes
Safety Precautions
• This activity is meant to have students design shoes that they might need to make in such a situation.
If you are going to have students make the shoes they design, extra materials and safety precautions
will be needed. For example, they will need goggles and an apron.
• Since food should not be brought into the science classroom, make up a mock sandwich package.
Hints and Helps
• If you decide to have students make their shoe design, collecting materials may be difficult depending
on the time of year. Consider using such materials such as:
– bottles made of thick plastic;
– old rags or clothes that will not be needed again; and
– old broad leaves (i.e., ones that have fallen) from a tropical plant at home.
• Students should not bring in their own knives.
Teaching Strategies
Plan to have fun with this activity. Act out the scene or simply have the students visualize the
following: As you crawl from the water and head for the shade, your bare feet are scorched by hot sand.
What do you need? Footwear!
Set the mood with one or more of the following:
• Play jungle music or ocean wave sounds during the introduction.
• Have students pretend that this is part of the Survivor television series. What will they do?
• Show a few minutes of a movie such as Castaway or Six Days, Seven Nights to set the scene of being
stranded on an island. Or, to stress the need for footwear on a desert island, show the scene in the
movie 10 where Dudley Moore is hopping across the hot sand of a beach.
• Have banana or palm leaves on hand for the students to touch, examine, and think about.
Implementing the Activity
• Students should study the picture to determine the materials naturally available on the island. There
are trees with large leaves — probably banana or palm trees.
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• Have students use BLM 6–1, Planning to Survive to help them plan their design.
• Remind students to:
– label all materials used on their footwear sketch;
– briefly describe the function of each material used; and
– have the design checked before beginning construction.
Meeting Individual Needs
LD Learners — Divide tasks between partners before starting the activity.
Persons with Physical Disability(ies) — If you decide to have students construct their design, students
may need the help of an adult supervisor to cut and construct the footwear. Alternatively, pair or group
students so they can help each other implement their designs.
Activity Wrap-up
• Discuss with the class what makes a good design.
• Student work can be evaluated by the teacher or by peers. One way of doing peer evaluation is to have
students place their sketches or finished shoes around the room. Each student is given four stickers
(dots, stars, etc.) that they place on the four designs they consider to be the best.
• If you have students construct their footwear, you may decide to allow them to test it on hot sand.
Prepare the hot sand before class as follows. Pour a bag of sand into a large basin or bucket. Insert the
bulb of a thermometer into the sand. Shine a 100W light or heat lamp on the sand for an hour or until
the sand temperature reaches 50°C. Have one student put on the designed footwear and stand on the
sand. If the student can stand comfortably for 30 seconds, the footwear design can be deemed
successful.
ASSESSING STUDENT LEARNING
ACTIVITY
Starting Point
Activity: Survivor
p. 105
OUTCOMES/CONCEPTS
– explain how technologies that
reduce heat transfer function
– describe three ways that heat is
transferred
– state a prediction based on
background information
– test the design of a constructed
device
– evaluate the design of a
constructed device
© 2002 McGraw-Hill Ryerson Limited
ASSESSMENT OPTIONS
– Discuss with the class what makes a good design.
– Post features of a good design.
– Use these points to evaluate the plan and the footwear.
– Student work can be evaluated by peer evaluation. One way
of using peer evaluation is mentioned in Activity Wrap-up.
– As an alternative to visual evaluation, footwear can be tested
as mentioned in Activity Wrap-up.
– Design Your Own Checklist
– Design Your Own Rubric
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6.1 Absorbing and Losing Heat (p. 106)
What Students Do in Section 6.1
In this section, students:
• learn about specific heat capacity;
• compare the speed at which different substances warm; and
• learn more about how water affects climate.
Science Background
Specific heat capacity is the amount of energy, in joules, needed to warm 1 g of a substance by 1ºC. For
instance, it takes 4.19 J to raise the temperature of 1 g of water by 1ºC.
The specific heat capacity of a substance can change depending on its state. For example, solid
water (ice) has a lower specific heat capacity than liquid water. This has to do in part with the relative
attraction between the molecules. Molecules that are close together, as in a solid, have a stronger
attraction to each other. They require more energy to get moving.
The joule is named after James Prescott Joule (1818–1899), a brewer and physicist. It is
represented by the symbol J.
Information about specific heat capacity values for substances other than those shown in Table
6.1 (on page 109 of the student textbook) should be available in the Chemistry 30 Data Booklet at your
school.
Teaching Strategies
There are two labs in this section. You may plan to follow the text in order, or have students work on
the activities before reading the text. This will give students a chance to discover first, then read about
and confirm what they have discovered. This method also provides an opportunity to have students
move through different work stations where each activity is set up. This has its advantages if supplies
are limited or if you wish to encourage independent work.
Use a discussion of everyday substances to draw observations about how substances heat and
cool at different rates. Some students may be involved in welding. Point out that when welding, the
starting temperature of the iron is higher than the highest temperature water can be. But iron cools
faster than water. Through their study of specific heat capacity, students will be able to perceive why
this is so. Other examples of the heating and cooling rates of different substances include bath water
staying hot for a relatively long time, liquid wax cooling and solidifying quickly, and an ice pack placed
on an injury slowly losing its cooling effect.
The following blackline masters will assist with various activities in this section:
• BLM 6–2, Keeping It Cool Worksheet; and
• BLM 6–3, Double the Water Worksheet.
Additional activities providing further practice with specific heat capacity concepts can be
found in BLM 6–4, Measuring as Solids Release Heat and BLM 6–5, Working with Specific Heat
Capacity.
Meeting Individual Needs
LD Learners — Read the student textbook section on specific heat capacity aloud. Allow time for the
information to be processed and understood. Be prepared to review and reread as necessary.
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Conduct an Investigation 6–A (p. 106)
Keeping It Cool
Purpose
• Students investigate whether liquids and solids absorb thermal energy at the same rate.
Advance Preparation
WHEN TO BEGIN
1 week before
1 day before
5 min before
APPARATUS
• hot plate
• 500 mL beakers
• graduated cylinder
• thermometer
• retort stand
• thermometer clamp
• stopwatch
• balance and masses
• stir sticks
WHAT TO DO
• Assemble or purchase any materials not available at school: motor oil, vegetable oil, marbles,
steel shot. (Shot is available in hardware stores.)
• Set aside a container of water (500 mL per group) to warm to room temperature.
• Assemble equipment for groups and set it out.
• Set up a station for pouring oil.
• Turn hot plates to medium temperature.
MATERIALS
• room-temperature water
• 250 mL of oil (such as mineral oil, paraffin, or motor oil)
• 250 mL vegetable oil
• glass marbles
• sand or 1 cm gravel
• steel shot (If steel shot cannot be found, any small metal pieces will do. It is important that
metal bits be small so heat will spread quickly.)
• oven mitts
• masking tape
BLM 6–2, Keeping It Cool Worksheet
Time Required
• 45–60 minutes, if hot plate is preheated.
Safety Precautions
• Handle all containers of hot substances with care.
• Inform students of first-aid procedures: If hot oil or water touches their skin, they should hold the
burned area under a stream of cold water for several minutes and have a fellow student inform you at
once of the incident.
• Wash your hands thoroughly at the end of the investigation.
• As students enter the classroom, caution them that the hot plates are preheated.
• Explain to the students that hot oil sticks to skin.
• Caution students and have a visible notice to the effect that oil is not to be heated above 60°C.
• Explain that hot oil droplets on a burner can ignite.
• Introduce the oil-pouring station.
Hints and Helps
• Handling oil can be messy. Contain the mess by having a pouring station with two or three graduated
cylinders.
• For easier clean-up, spread newspaper or plastic sheets in the oil-pouring area.
• Make sure you have a supply of room-temperature water so all substances will have the same starting
temperature.
• Preheat the hot plates. This is especially important with old hot plates.
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• Clamping thermometers to retort stands ahead of time will prevent students from using them as
stirring sticks.
• If you have many thermometers and retort stands available, and if your hot plates are big enough,
consider heating the three containers (water and the two oils) on the hot plate at the same time.
• If convenient, leave the clamped thermometers assembled. They will be used again in the Find Out
Activity that follows.
• Steel nails can be used if steel shot is not available.
Teaching Strategies
If time or materials are limited, consider having half the class work on Part 1 and half on Part 2 of the
investigation. Groups may switch when finished.
Students should work on this investigation in pairs. If space is limited, have half the class do the
lab while the other students work at their desks.
Implementing the Investigation
• Provide students with copies of BLM 6–2, Keeping It Cool Worksheet to record their data.
Meeting Individual Needs
Persons with Physical Disability(ies) — Students in wheelchairs may need low tables provided with
spill trays. If hot oil is spilled, it will stay in the tray rather than pour onto the student’s lap.
Visually Impaired — Provide students with wide-mouthed, pre-taped cylinders for measuring liquids.
Pair students with another student who can help.
Learning Styles — Students with learning problems will benefit if group size is kept small to allow
maximum individual participation.
Investigation Wrap-up
• Have groups answer questions together after finishing each part of the activity.
• Encourage students to illustrate information from the investigation in a bar graph.
– Students may use information from BLM 5–12, Use a Spreadsheet Program to Make a Bar
Graph or BLM 5–11, How to Construct a Bar Graph.
– Before students start their graphs, discuss any changes needed to the x-axis and y-axis.
• Discuss students’ identification of variables. Should other variables have been considered? How were
students able to control variables to make a fair test?
Analyze Answers
Part 1
1. Water.
2. The oils. They are similar substances, very different from water, so their heat capacity would be
closer.
Part 2
3. Glass.
4. Glass and sand. Glass is made from sand.
Conclude and Apply Answers
5. (a) Yes.
(b) Liquids took longer to change temperature. They needed to take in more heat for a change in
temperature to occur.
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Extend Your Knowledge Answer
6. Look for points such as the following.
• In sunlight, sand needs only a little heat to become hot.
• Sand will heat much faster than water.
• He dances because his feet are burning. Her feet are in cool water.
Extensions for Activity
• {AB.Sc14.B.K.2.iii}
In Part 2, instead of heating the solid materials and timing how long it takes to raise the temperature,
students can reverse the procedure.
Use the hot water saved from Part 1 to heat the same three substances. Then measure how this
thermal energy is released. If you choose to do this activity, use BLM 6–4, Measuring as Solids
Release Heat to guide students.
There are two advantages to this alternative. First, by using leftover water from Part 1, it takes
less time. Second, it demonstrates clearly a concept that is sometimes difficult to understand:
substances at similar temperatures can hold different amounts of thermal energy.
• {AB.Sc14.B.S.1.iv}{AB.Sc14.B.S.1.v}
Begin the investigation by having students develop hypotheses and make predictions for Parts 1 and 2
of the investigation using an “if..., then...” formula. (Example: “If the liquids are different, then the
time it will take to heat them 30ºC will be different.”) Students should complete the hypotheses
before starting their investigation.
ASSESSING STUDENT LEARNING
ACTIVITY
Conduct an Investigation
6–A: Keeping It Cool
p. 107
OUTCOMES/CONCEPTS
– describe variation in the ability of
different substances to absorb heat
– design and perform an experiment
– use instruments for collecting data
– interpret patterns and trends in data
ASSESSMENT OPTIONS
– Assess how students work with others.
– Is work shared?
– Do one or two dominate the work?
– Students should note that water takes about
twice as long to rise the required amount.
– Students should get heat transfer for minerals
in the correct order.
– Conduct an Investigation Checklist
– Conduct an Investigation Rubric
– Lab Report Checklist
– Lab Report Rubric
– Using Tools and Equipment Checklist
– Using Tools and Equipment Rubric
Find Out Activity (p. 108)
Does Double the Water Take Double the Time to Boil?
Purpose
• Students learn that it takes twice as long to heat twice the amount of water.
• Students find that warm water heats at the same rate as cold water.
Advance Preparation
WHEN TO BEGIN
1 day before
10 min before
WHAT TO DO
• Set out water in a large container to warm to room temperature. Plan on ¾ L (750 mL) of
water per group.
• Photocopy BLM 6–3, Double the Water Worksheet.
• Turn hot plates to medium temperature.
© 2002 McGraw-Hill Ryerson Limited
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APPARATUS
• 500 mL beaker
• thermometer
• clamp and stand
• hot plate
MATERIALS
• water
BLM 6–3, Double the Water Worksheet
Time Required
• 20–30 minutes
Safety Precautions
• Remind students to be careful when using hot water.
• Caution students not to allow water to get hotter than 70ºC.
Prediction
• As they begin this activity, students should make predictions. Heating water is something we do every
day; making predictions may help bring some preconceived notions about water into the light, to
either prove or dispel them.
Hints and Helps
• Emphasize that 1 mL of water is the same as 1 gram of water. In fact, that is what defines the mL
volume. Do this now and avoid confusion later when discussing specific heat capacity in terms of
grams, not mL.
• If there is a microwave oven available, you may wish to perform the following demonstration. Place
100 mL cold tap water in each of two microwave-safe cups. The water should be the same temperature.
– Heat the first for 15 sec. Remove from oven and record the temperature.
– Heat the second for 30 sec. Remove from oven and record the temperature. Do not put the
thermometer in the microwave.
– Repeat, starting with lukewarm water. (Do not use water so hot it will boil when heated.
Temperature change will cease once the water begins boiling. This will alter expected results.)
Teaching Strategies
Consider having half the class study what effect doubling the water has on temperature change, while
the other half studies the effect of having different starting temperatures.
Have students work in small groups. You might wish to orchestrate the composition of the
groups.
Implementing the Activity
• Identify major variables and plan to control them.
• Students should use BLM 6–3, Double the Water Worksheet to record their data.
Activity Wrap-up
• Students may answer questions in groups or individually as they finish the lab work.
• Discuss the results of the activity as a class. Have students review their original predictions.
What Did You Find Out? Answers
1. Yes.
2. Findings stayed the same.
© 2002 McGraw-Hill Ryerson Limited
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ASSESSING STUDENT LEARNING
ACTIVITY
Find Out Activity:
Does Double the Water
Take Double the Time to
Boil?
p. 108
OUTCOMES/CONCEPTS
– describe variation in the ability of
different substances to absorb heat
– use instruments for collecting data
– calculate theoretical values of a
variable
– interpret patterns and trends in data
ASSESSMENT OPTIONS
– Observe and assess the care students take in
measuring both volume and temperature.
– Assess quality of work on tables and charts.
– Scientific Concepts Checklist
– Scientific Concepts Rubrics
Reading Check Answer (p. 108)
Specific heat capacity is reported in joules per gram degrees Celsius, or J/g•°C.
Try This! (p. 109)
1. There should be a direct correlation between what students found in Conduct an Investigation 6–A
and specific heat capacity of liquids.
2. There should be agreement between what students found in Conduct an Investigation 6–A and
specific heat capacity of solids.
Did You Know? (p. 110)
The fire-walkers’ secret is out! Some students will realize we use the specific heat capacity of water in
a similar way when we wet a finger and touch an iron quickly to see if it is hot enough. The water turns
to steam but the high specific heat capacity of water keeps the finger from burning.
Reiterate the “Caution” in the text. Fire-walking is not a stunt they should try on their own.
Science Myths (p. 110)
Most students will have seen this phenomenon, but it may not have registered. You can bring in an
electric kettle for an in-class demonstration. Ask what students think the cloud is made of. How do they
explain the space between the spout and the cloud? Some students might be surprised to hear that the
cloud is not water vapour, but fine water droplets.
Section 6.1 Review (p. 110)
Key Terms Teaching Strategies
• Recall with students the meaning of each of the terms. By now each student should have heard and
used each term a number of times.
• Have students write definitions for each key term in their Science Log or notebook.
Check Your Understanding Answers
1. (a) Beaker B. It will require twice the energy since it has twice as much water in it.
(b) Beaker B. It will require more energy because it must be heated 10°C more than Beaker A.
(c) Beaker A. It will require more energy because water has a greater specific heat capacity than oil.
Water takes much more thermal energy than an equal quantity of oil to increase its temperature by
the same amount.
2. Beaker A. Water has a higher specific heat capacity than sand, so Beaker B will need less heat.
3. Due to water’s greater specific heat capacity, water needs much more heat from the Sun to change its
temperature than sand does. The water at a beach during the day really is cooler. On a sunny day,
water takes longer to heat up than the sand. Similarly, at night, sand cools quickly but water hold its
© 2002 McGraw-Hill Ryerson Limited
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heat. Water must release much more thermal energy to lower its temperature, so the water feels
warmer at night.
4. Water has a higher specific heat capacity than oil. Water can absorb much more heat from a hot
engine than oil can.
5. If you want to have very hot oil, it is easier to heat oil with a lower specific heat capacity. This oil
will heat up fast with less energy. Also, an oil with a low specific heat capacity would be less likely
to burn the French fries.
Extensions for Section 6.1
• {AB.Sc14.B.K.2.iii}{AB.Sc14.B.S.3.ii}
For practice in calculating specific heat capacity, students may complete BLM 6–5, Working with
Specific Heat Capacity.
• {AB.Sc14.B.K.2.iii}
Amazing Water (I): Flameproof Paper
Demonstrate how water’s specific heat capacity makes it an amazing substance. Do this
demonstration before discussing specific heat capacity. Explain what you will do and ask students to
predict what will happen.
You will need a paper cup, candle or Bunsen burner, retort stand and ring, and tin pan.
Fill the paper cup with water. Place it in a small ring clamp attached to a retort stand. Bring a lit
candle to touch the bottom of the paper cup. To everyone’s surprise, the paper will not burn and after
about 10 minutes the water will start to boil!
If the water is slow to boil, use two candles or a Bunsen burner set on low. Too high a Bunsen
flame will cause the top of the cup, the part not touching water, to burn.
If the class thinks you are cheating with some type of magic cup, dump the water after it has
boiled and burn the cup. It will ignite immediately once all the water droplets have evaporated. Put
the burning cup into the pan.
• {AB.Sc14.B.K.2.iii}
Amazing Water (II): Trusting in Science
As above, do this demonstration before discussing specific heat capacity. Explain what you will do
and ask students to predict what will happen.
Practise this demonstration in private before showing the class. You will need a round balloon,
candle, matches, cold water, and a small umbrella or a hard hat.
Fill the balloon no more than ¼ full of water. Tape or glue the candle to the top of the open
umbrella or hard hat. Light the candle. Either hold the umbrella over your head or wear the hat with
the lit candle on it. Have a student hold the balloon in the flame. (Either sit down, or have the student
stand on a chair to reach.)
Students will expect the balloon to break and drench you; to their surprise — or disappointment
—the balloon will not pop. (Note: The balloon will pop if the student does not hold the water-filled
part of the balloon over the candle. Choose the student carefully.)
To conclude, hold the balloon over a sink and slowly move the flame away from the watercovered part of the balloon to an area where there is only air; the balloon will pop immediately.
Explain that water will not let the balloon or the paper reach its kindling point (the point at which a
substance will catch fire). As long as the water is touching the surface that is being heated, the
material will not ignite or break.
ASSESSING STUDENT LEARNING
ACTIVITY
Section 6.1
pp. 106–110
© 2002 McGraw-Hill Ryerson Limited
OUTCOMES/CONCEPTS
– describe how devices that protect
against potentially dangerous heat
transfer function
ASSESSMENT OPTIONS
– Question 1 of Check Your Understanding
represents the essence of what students need to
know about specific heat capacity.
12
– describe variation in the ability of
different substances to absorb
heat
– explain technologies that reduce
heat transfer
– describe the role of convection
and conduction in distributing
heat
© 2002 McGraw-Hill Ryerson Limited
– Students complete Check Your Understanding
questions.
– Students submit answers for grading or
classroom discussion of questions to ensure
understanding.
– Science Concepts Checklist
– Science Concepts Rubric
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6.2 Keeping Heat at Home (p. 111)
What Students Do in Section 6.2
In this section, students:
• learn about insulators and insulation;
• discover that R-value is a measure of heat transfer;
• design devices for keeping things cold and hot;
• learn how reflective surfaces can act as insulators; and
• investigate ways in which heat transfer can be minimized in a home.
Science Background
With energy costs rising, Canadians want to make sure heat stays inside the house in winter. For
Canadians, 50 to70 percent of energy costs go toward heating or cooling our homes. If insulation is
inadequate, much energy is wasted. This is bad for the environment and for the home budget.
Energy is always seen to move from hot to cold. The old saying, “Don’t let the cold in” is
inaccurate. It is correct to say, “Don’t let the heat out.”
Insulation reduces heat transfer. A good insulator is the opposite of a good conductor. With
good insulation, the three forms of heat transfer are slowed. Heat convection and heat conduction can
be minimized in two ways. First, create a partial vacuum between the areas to be insulated. This is done
in vacuum bottles and in some double-glazed windows with an inert gas between the panes. Second,
use trapped air. Still air provides 15 000 times better insulation than metal.
Substances used for insulation are chosen for their low thermal conductivity and their ability to
trap air. Good conductors include cork, felt, cotton batting, magnesium carbonate, and spun glass or
fibreglass. Asbestos is an excellent insulator but it is a health hazard and no longer used in construction.
A general guideline is that wall insulation should have an R-value of 11 and ceilings should
have an R-value of between 19 and 31.
Insulators work best when the air is dry. Moist air acts as a much better heat conductor than dry
air. To keep insulation dry, fibreglass is covered with plastic sheeting before drywall is installed.
Without the plastic sheet, moisture from inside the house — from cooking, bathing, and breathing —
would infiltrate the insulation and reduce its effectiveness.
Radiant heat loss can be lessened by installing aluminum foil, semi-reflective windows, and
metal roofing.
To find out more about home insulation and heat efficiency, go to
www.mcgrawhill.ca/links/science.connect1, then to Teacher Resources, Web Resources, Unit B,
Chapter 6, and Home Insulation.
Teaching Strategies
Many activities in this section require materials not normally found in school supplies. Ask students for
help in finding materials for labs when necessary.
Some activities, such as Think & Link Investigation 6–C and Design & Do Investigation 6–D,
may require more than one class. Depending on your time and resources, you may wish to modify some
of these activities. Devise a plan that works best for you and your class.
Consider taking the class on a field trip to a store or business that specializes in supplying or
installing home insulation. Many of the larger stores have demonstration areas or hands-on workshops
where students can become acquainted with these materials. Alternatively, invite a guest speaker —
perhaps someone from one of these businesses, or a person with expertise in house construction. This
speaker can bring in examples of insulation and other energy-saving devices.
© 2002 McGraw-Hill Ryerson Limited
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Obtain videos that discuss home insulation. Many large building supply stores have centres
where do-it-yourself videos can be rented for a nominal fee.
Consider posting a reading guide as the class prepares to work on the chapter. To help students
grasp the ideas contained in this section, include specific questions, such as:
• List two ways insulation benefits the homeowner.
Insulation keeps heat in during the winter and out during the summer.
• What do the numbers of R-value tell you?
R-value indicates how well a material insulates.
• Which is a better insulator material: R-12 or R-16?
R-16 is a better insulator.
• Which is a better insulator: solid wood or wood shavings?
Wood shavings insulate better.
The following blackline masters will assist you with various activities in this section:
• BLM 6–6, Working with R-Value;
• BLM 6–8, Heating the Whole Neighbourhood.
BLM 6–7, Another Insulation Test provides an alternative activity for students to further
investigate the efficiency of various materials as insulators.
Meeting Individual Needs
LD Learners — Students who read slowly may need to reread the section on R-value (page 111 of the
student textbook). They may benefit from a paragraph-by-paragraph reading guide as mentioned in the
Teaching Strategies section.
Alternative Activities
• {AB.Sc14.B.K.1.ii}{AB.Sc14.B.K.2.i}{AB.Sc14.B.K.1.iv}
Have students use BLM 6–7, Another Insulation Test to test materials for their ability to insulate.
Caution students to be careful when working with electrical apparatus.
• {AB.Sc14.B.K.1.iv){AB.Sc14.B.K.2.i){AB.Sc14.B.K.2.ii)
Have students use the library and the Internet to research ways that animals and plants use snow for
shelter, including designs of different types of snow shelters. Encourage students to use personal
interviews to gather information as well. They can contact Aboriginal groups, outdoor suppliers and
guides, and youth groups such as Scouts for information about using snow as an insulator.
• {AB.Sc14.B.K.1.iv){AB.Sc14.B.K.2.i){AB.Sc14.B.K.2.ii){AB.Sc14.B.S.2.iii}{AB.SC14.B.S.3.iii}
{AB.Sc14.B.S.3.iv}{AB.Sc14.B.S.3.v}{AB.Sc14.B.S.3.vi}{AB.Sc14.B.S.4.i}{AB.Sc14.B.S.4.ii}
If conditions permit, have the class build a quinzhee, a southern-latitude igloo.
1. Mark out a circle on the snow approximately 4 m in diameter.
2. Shovel snow into the centre.
3. When the pile is about 2 m high, pack it down with the back of the shovel.
4. Let the pile settle for an hour or two.
5. Check wind direction and choose a spot for a door. (Wind should blow across the door opening,
not into it.) At the selected spot, dig snow down to ground level.
6. Dig out the door opening. Keep the door as low as possible. Start to hollow out the mound of snow.
7. As you dig into the mound of snow, dig left and right of the door as well.
CAUTION: Be careful while digging to avoid the structure collapsing. Dig out the dome as well so
there will be only a small mass of snow above you.
8. A wall and ceiling thickness of 15–20 cm is quite strong. Some builders put small sticks 20 cm into
the dome. They know the ceiling is the right thickness when they uncover the ends of the sticks on
the inside. Others have found that hollowing out the dome until daylight shows through the snow
provides the right thickness.
© 2002 McGraw-Hill Ryerson Limited
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9. When you have finished excavating, the dome must be coated with ice. Burn a page of newspaper
inside the quinzhee. Block the door while it burns. Alternatively, place a lit candle inside for 20
minutes with the door blocked.
This is a basic quinzhee. Discuss with students how heat will escape. Where will the warmest
place be? If you were to sleep here for the night, you would want to make improvements: a raised
sleeping platform would keep you warmer; an air hole would keep air fresh; blocking the door would
help keep heat inside.
Many outdoor education schools will give instruction on how to build effective snow shelters.
Some may be willing to demonstrate this skill for the class.
Consider an overnight field trip where students would build snow shelters and sleep in them.
Contact an outdoor education company that specializes in running these types of programs.
This activity demonstrates that snow is a good insulator and reinforces the importance of
trapped, still air in insulation. By compacting the snow, students appreciate how much air there is in
light snow.
• {AB.Sc14.B.K.2.ii}{AB.Sc14.B.S.1.iv}{AB.Sc14.B.S.1.v}
Have the class design an investigation to compare the insulating qualities of snow. Is snow as good an
insulator as fibreglass? Adapt the equipment used in BLM 6–7, Another Insulation Test for this
activity.
• {AB.Sc.14.B.K.2.i}{AB.Sc14.B.S.1.iii)
With the cost of fuel rising, students may wish to evaluate the energy efficiency of their own homes.
Have students tour their own home and draw up a report on how they could save on their household’s
monthly heating bill.
Before starting this assignment, consider having a heating expert come in to do a presentation
on different ways to cut heating costs
As some adults may wish to keep information about their home private, students should ask for
parental consent before conducting the study and making their report. Students might consider
proposing a plan as to how their recommendations could be implemented and the costs involved. As
an incentive, such a plan could suggest that the student share a portion of the future savings.
Reading Check Answer (p. 111)
An insulator slows heat transfer.
Conduct an Investigation 6–B (p. 112)
Ice Sculptures
Purpose
• Students discover that some insulators transfer more thermal energy than others.
Advance Preparation
WHEN TO BEGIN
1 week before
2–3 days before
10 min before
WHAT TO DO
• Gather materials not usually found in the school.
– coffee cans: ask staff/students to collect them
– foam pellets and bubble wrap: these may be available free at electronics or computer stores
– poured insulation: available at a local hardware store
– wood shavings: check with the school’s woodworking shop or local pet stores
– ice cubes: buy a bag, or make in ice-cube trays
• Check that all materials are put aside and ready for use.
• Bring ice cubes from the freezer to the class.
© 2002 McGraw-Hill Ryerson Limited
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APPARATUS
• scale or balance (1 for every 2 groups)
• 6 coffee cans with lids
• large basin — must fit 6 coffee cans at once
• thermometer
MATERIALS
• ice cubes of similar size and shape
• resealable plastic bags
• paper towels
• foam pellets (peanut-sized)
• wood shavings
• aluminum foil
• poured insulation
• plastic bubble wrap
Time Required
• 45–60 minutes
Safety Precaution
• Use care when handling the coffee cans.
Prediction
• Students will look at this challenge from widely different background experiences. Each of the
insulators chosen has been used to insulate and is a good insulator at times. It is not a major fault to
rank any of these incorrectly at this point. One value of this activity is for students to talk through why
they think one substance is a better insulator than another.
Hints and Helps
• Once materials are collected, make a kit to save materials for future use.
• Depending on class size and when you start gathering supplies, it may be difficult to obtain enough
coffee cans. Consider using the following as an alternative, fashioning lids from aluminum foil:
– pop cans with the tops cut off;
– soup cans; or
– 400–500 mL lab beakers.
Groups may use different types of containers, as long as all six containers in any one group are
the same.
There may be a tendency for the cans to float. This can be overcome by keeping the water bath
shallow and placing something heavy, such as a book or piece of wood, on top of the cans.
• Consider using insulating materials available around the house (such as wool blankets or scarves,
shredded newspapers, or popped popcorn) instead of foam pellets.
• Label the cans and plastic bags so that the source of each ice cube (which bag it came from) will be
known when students are weighing ice cubes at the end.
Teaching Strategies
To speed up the activity and to ensure participation, divide the class into groups of five. Each member
will be responsible for setting up one can. The last can is empty; it acts as a control.
Working in a group can be difficult for students. Use Figure 10.1 Guidelines for Co-operative
Learning in this Teacher’s Resource to plan with students to make this activity a success.
Start the lab at the beginning of a class. Once the ice cubes are warming, there is a 30-minute
wait time. Plan to do another activity while waiting, such as:
• Read and discuss insulation and R-value.
• Review the manipulated variable (type of insulation) and responding variable (amount of ice cube
melt) with students. Focus on controlling all other variables, such as:
– the amount of insulation;
– the way the insulation is packed;
© 2002 McGraw-Hill Ryerson Limited
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– where the ice cube is placed in the can; and
– the position of the can in the warm bath.
• Have students assess what they have just done and decide if they should start over. Remind them there
is no shame in starting over; scientists do it all the time.
Implementing the Investigation
• Supply students with, or allow them time to make, a table similar to Figure 6.1.
Figure 6.1 Ice Cube Mass Loss
Insulation Material
Initial Mass (g)
Ice Cube
Final Mass (g)
Mass Lost (g)
A wood shavings
B foam pellets
C bubble wrap
D poured insulation
E aluminum foil
F empty can
Analyze Answers
1. Answers will vary. The ice in the empty can should melt the most. Most of the time, poured
insulation or foam should melt the least, but it depends on pellet size and composition of insulation.
2. Answers will vary. This might get the class into a discussion on thickness of insulation. Wood
shavings or sawdust might prove to be a very good insulator if thickness of insulation was planned
poorly. A second look at Table 6.2 on page 111 of the student textbook might help the discussion.
3. Answers will vary. The empty can is not a valid answer, because there was no insulation in the can.
4. Answers will vary.
(a) • the same type and size of container
• a similarly sized ice cube
(b) • thickness of insulation (difficult to control)
• time between massing the cubes to wrapping them (difficult to control)
Conclude and Apply Answers
5. The answer might be the substance they chose in question 1, the insulator that allowed ice to melt
least. This insulator will probably be fibreglass or foam pellets.
6. The ice blocks would have to be insulated to prevent them from sticking together.
• Foam chips would not be ideal because of the difficulty of holding them in place.
• Sheets of bubble wrap would be easier to position.
• Students should realize that some good insulators have inherent problems that make them either too
difficult or too expensive to use. An insulator that is cheaper or easier to use may be suggested for
this reason. Sawdust, wood shavings, and bales of straw have been used for many years to insulate
ice.
• Students might mention that aluminum foil was much thinner than any of the other insulation. It
may be hard for them to understand that the insulation value of foil is in its reflective property, not
its thickness.
Extend Your Knowledge Answers
7. Answers will vary. Examples include:
• Pack ice in a refrigerated truck.
• Transport ice at night when the outside temperature is cooler.
• Pack an extra, insulating layer of ice around the blocks.
© 2002 McGraw-Hill Ryerson Limited
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• Arrange the blocks in a cube to minimize surface area.
8. Yes. It does not matter whether things are to be kept hot or cold. An insulator’s job is to slow energy
transfer. Insulators work the same whether the heat is travelling from the outside in, or the inside out.
Extension Activities
• {AB.Sc14.B.K.2.i}{AB.Sc14.B.S.3.i}
Students complete a class chart similar to Figure 6.2, on which they note the mass of the ice lost for
each insulator. To do this, students use an electronic balance to determine the mass of ice before the
investigation. They remove the remaining ice, dry it quickly on a paper towel, and use the balance to
calculate the mass of ice after the investigation. They then subtract the original mass of ice from the
mass of ice remaining to determine the mass of ice lost for each insulator.
Have a class chart ready. As groups complete the “Mass Loss” column, they can enter the
figures in the class list. When the chart is complete, work as a class to find the average mass lost for
each insulator. Have students graph the results on a bar graph. Discuss whether this calculation
provides a better way of finding the best insulator.
Figure 6.2 Mass Loss Table
Mass Loss for Insulation Tested
Groups
Wood
Shavings
Foam
Pellets
Bubble
Wrap
Poured
Insulation
Aluminum
Foil
Control
(empty)
• {AB.Sc14.B.K.2.i}{AB.Sc14.B.S.3.i}{AB.Sc14.B.S.2.ii}
Use a class chart similar to Figure 6.2 to compare results of Investigation 6–B. Students rank their
results and rank insulation materials on a scale of 1 to 5, where 1 is the best and 5 the worst insulator.
– Have a class chart ready. As groups complete the “Mass Loss” column, they can rank the insulators
and enter the figures in the class ranking list.
– Look for common findings.
– Look for discrepancies and discuss possible causes.
ASSESSING STUDENT LEARNING
ACTIVITY
Conduct an Investigation
6-B: Ice Sculptures
p. 112
OUTCOMES/CONCEPTS
– explain technologies that reduce heat
transfer
– use instruments for collecting data
– evaluate a design in terms of use of
materials
– interpret patterns and trends in data
– identify and correct practical problems
in a constructed device
© 2002 McGraw-Hill Ryerson Limited
ASSESSMENT OPTIONS
– Compile anecdotal notes on how students
work in groups.
– Assess tables and graphs for neatness and
accuracy.
– Assess answers for Conclude and Apply and
Extend Your Knowledge.
– Conduct an Investigation Checklist
– Conduct an Investigation Rubric
– Lab Report Checklist
– Lab Report Rubric
– Co-operative Group Work Checklist
– Co-operative Group Work Rubric
19
Find Out Activity (p. 114)
Will Aluminum Foil Keep You Warm?
Purpose
• Students investigate the insulating value of aluminum foil.
Advance Preparation
WHEN TO BEGIN
1 day before
WHAT TO DO
• Set up materials.
APPARATUS
• 2 beakers (500 mL)
• 2 thermometers
MATERIALS
• source of hot water (e.g., electric kettle)
• aluminum foil
Time Required
• 40 minutes
Safety Precautions
Hints and Helps
• If a hot water tap in the classroom does not provide water at close to 60°C, arrange to heat sufficient
water to that temperature before class.
Teaching Strategies
There is a waiting period of 30 minutes in the middle of the lab. Prepare to carry out another activity or
lesson during this time.
Alternatively, you may choose to demonstrate this activity during the break in Investigation 6–
B.
Implementing the Activity
• Remind students that everything except the presence or absence of aluminum must be strictly
controlled (i.e., amount of water, temperature of the water, size of beaker, and placement of beaker).
They should leave both beakers uncovered.
Activity Wrap-up
• Discuss how foil and its ability to reflect heat is used in everyday products. Examples include:
– for emergency lightweight blankets
– as a lining in gloves and outerwear
– as a lining in ovens
– in vacuum bottles and insulated jugs
• Review the role aluminum might play in students’ footwear designs for the Starting Point Activity.
How would they modify their designs now?
What Did You Find Out? Answers
1. The beaker that was not covered with aluminum foil.
2. Answers will vary, but the foil-covered beaker will be noticeably warmer.
3. Heat transfer from the beaker is slowed.
© 2002 McGraw-Hill Ryerson Limited
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Conclude and Apply Answers
4. • The R-value for air space is 2.04.
• The R-value for a space with a reflective surface on the inside is 5.54.
• Foil insulates the wall cavity much better than an air space alone.
• Yes, the results should agree with the table.
Assessing Student Learning
ACTIVITY
Find Out Activity:
Will Aluminum Foil Keep
You Warm?
p. 114
OUTCOMES/CONCEPTS
– explain technologies that reduce heat
transfer
– identify questions to investigate arising
from practical problems and issues
– identify potential applications of
findings
ASSESSMENT OPTIONS
– Assess student answers for What Did You
Find Out question 3.
– Ask students to check uses of foil at home.
– Using Tools and Equipment Checklist
– Using Tools and Equipment Rubric
– Scientific Concepts Checklist
– Scientific Concepts Rubric
Reading Check Answer (p. 115)
Modern homes keep heat in using:
• insulation in walls and roofs;
• double-glazed windows and doors;
• insulated doors; and
• caulked leaks between windows and/or doors and walls.
Did You Know? (p. 115)
A 1 mm crack around a window will result in an average loss of 1 L of fuel per day. Using current fuel
price information, work with students to see how much this would cost during one heating season.
Career Connect (p. 115)
Houses that are airtight get humid. Water condenses on glass and runs down windows. This can ruin
woodwork and wallpaper. New houses are designed to overcome these problems while maintaining
high energy efficiency. Active ventilation is used to blow air out of the house. Passive walls leak by a
calculated amount. There are many ways to learn how to build a house; as with other skills, when you
learn the “old ways,” you can sometimes repeat old errors.
Try This! (p. 115)
Very light thread, flagging tape, or Christmas tinsel can be used in a similar way. Smoke is a good draft
detector, but presents some hazards that the other methods do not. (Cigarettes are unhealthy, candles
can drip wax, flames can ignite drapes around windows, etc.) Do not recommend that students use
smoke to detect drafts.
Think & Link Investigation 6–C (p. 116)
Energy Efficiency
Purpose
• Students inspect the school building, evaluating it for heat loss and insulation improvement.
Advance Preparation
WHEN TO BEGIN
1 week before
WHAT TO DO
• Collect or prepare materials.
© 2002 McGraw-Hill Ryerson Limited
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1 day before
• Check that all materials are put aside and ready for use.
• Depending on the expectations of your school, tell the administration of your plans.
APPARATUS
MATERIALS
• paper
• pencil
• tissue used as a breeze detector
• photocopied maps of the school
• overhead of the school map
Time Required
• 30 minutes
Teaching Strategies
The results of this activity will depend on the different methods of insulation used in your school.
Before working on this activity, consider inviting a heating professional to the class to discuss modern
insulating techniques.
Use BLM 6–8, Heating the Whole Neighbourhood as a warm-up exercise to help students
start looking at places where heat loss occurs.
Give students specific goals, such as “You are responsible for finding one heat-loss site for
every three minutes you are gone.”
Keep group size small to increase workload of each student and raise accountability.
Allow only half the groups to leave the classroom at one time. Be specific as to what time the
students should be back in the classroom.
Separate groups geographically by assigning each a different area of the school to investigate.
Be clear about consequences for disrupting other classes or returning late from this assignment.
If you deem it unwise to allow students to work unsupervised in the hallways, students could
investigate heat loss within the classroom instead of the entire school.
Alternatively, if your school has few kinds of insulation, consider doing this as a whole class
activity during which students brainstorm the different ways to prevent heat loss. They could use the
school, their homes, and other buildings as examples.
Implementing the Activity
• If you feel it is necessary, give students hints about what to look for and/or where to look.
• Students will mark areas that need to be improved on their school maps and return to class to make
notes and complete suggestions.
Meeting Individual Needs
Persons with Disability(ies) — Students with mobility difficulties may wish to limit their investigation
to heat loss in the immediate classroom environment.
Investigation Wrap-up
• Have students mark improvements on a larger map in the classroom.
• Students should summarize their results, and present their findings to the class.
• Before students start on the Analyze questions, discuss the cost of workers and of materials with
them.
– Cost of qualified workers is a large part of the cost of any job. With many jobs, cost of materials is
the same as the cost to get a worker to install the material.
© 2002 McGraw-Hill Ryerson Limited
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– Advertisements from newspapers will give students a good idea of the costs involved in increasing
energy efficiency in the school. Replacing windows, for instance, is an expensive job that must be
budgeted for.
– Students might complete a School Insulation Planning Chart similar to that in Figure 6.3. They will
then see which jobs are likely to be financially possible, and which are not.
• Assign the Analyze questions and try to create a forum for discussion of the answers.
Figure 6.3 School Insulation Planning Chart
Suggested
Improvement
Cheap Materials /
Little Worker Time
Expensive Materials
more than $***.**
More than a Week
of Worker Time
Analyze Answers
1. Students can use Table 6.2 on page 111 of the student textbook to get some idea of how their
improvements will increase R-value. Some are hard to gauge. Is the R-value of closing a crack under
a door the same on a windy day as on a calm day?
2. Answers will vary and are subjective. Students should discuss how they can measure heat loss.
3. Answers will vary. Examples might include caulking windows, installing double glazing, etc.
4. Look for persuasive arguments, documentation, and appropriate language. Encourage students to
focus on a few of what they deem to be the most important, most possible suggestions. You may
wish to invite the students’ language arts teacher to use this report as a cross-curriculum activity.
Extend Your Skills Answer
5. Answers will vary. Examples might include caulking windows, installing double glazing, insulating
an attic, etc.
ASSESSING STUDENT LEARNING
ACTIVITY
Think & Link
Investigation 6–C:
Energy Efficiency
p. 116
OUTCOMES/CONCEPTS
– explain technologies that reduce heat
transfer
– propose alternative solutions to a given
practical problem
– evaluate designs in terms of materials
used
– estimate measurements
– identify and correct practical problems
ASSESSMENT OPTIONS
– Assess student behaviour around the school as
they work on their own.
– Assess quality of suggestions. Are they
possible? Are they reasonable?
– Report to the school administration should be
in good English and easy to understand.
– Scientific Concepts Checklist
– Scientific Concepts Rubric
– Scientific Communication Checklist
– Scientific Communication Rubric
Off the Wall (p. 116)
R-30 insulation would let 1/30 of the heat pass through. (The number that accompanies the R-factor
becomes the denominator of a fraction; the numerator is one.)
For a visual demonstration, ask students to do the following.
• Draw a rectangle 24 cm x 2 cm on a blank piece of paper.
• Divide the rectangle into four equal parts. Shade one part, and write R-4 over that part. R-4 insulation
lets one quarter of the heat pass through.
• Continue dividing the rectangle. This time divide each quarter in half, for eight equal parts. Using
another colour, shade one eighth of the rectangle. R-8 insulation lets one eighth of the heat pass
through.
© 2002 McGraw-Hill Ryerson Limited
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• Continue dividing the rectangle to sixteenths, thirty-seconds, and sixty-fourths.
• Students should now be able to appreciate that there is a great difference between R-4 and R-8 but a
lesser difference between R-32 and R-64.
If students have not yet done BLM 6–6, Working with R-value, this would be a good time to
do it.
Reading Check Answer (p. 117)
Foil and silver paint reflect heat. On an outer surface, they reflect heat away from
the object. On an inner surface, they reflect heat back inside the object.
Try This! (p. 117)
Reflective surfaces are used around the home to slow heat transfer in ovens, refrigerators, dishwashers,
furnace and other heating ducts.
Design & Do Investigation 6–D (p. 118)
When You’re Hot ...
Purpose
• Students use their knowledge of heat transfer and insulators to make an insulated jar.
Advance Preparation
WHEN TO BEGIN
1 week before
1 day before
WHAT TO DO
• Begin collecting supplies.
• Enlist students’ help to collect materials.
• Assemble all materials.
APPARATUS
• 2 glass jars with metal lids (per group)
• foam chips
• thermometer
MATERIALS
• plastic bags
• wool blankets or scarves
• aluminum foil
• newspapers
• Styrofoam™ pellets (or popped popcorn)
• grey duct or electrician’s tape
• string
Time Required
• 40–60 minutes
Safety Precautions
• Caution students to be careful when working with very hot liquids.
Hints and Helps
• Tell students about this project in advance. Have them bring disposable materials from home.
• It may be difficult to find enough glass jars. Ask students to bring in glass jars from home. Instant
coffee jars and jam jars are two possibilities. Stress that the two jars used by each group must be
similar.
Teaching Strategies
© 2002 McGraw-Hill Ryerson Limited
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Divide the students into groups for planning, but consider having students make their own individual
insulated jar.
Keep students focused by making this a timed project.
If you decide to give prizes, there are many attributes to reward other than best insulator. These
include lightest, least bulky, easiest to drink out of, best handle, and handiest lid.
Potential difficulties caused by the four-hour waiting period in this activity can be overcome as
follows:
• Have a designated student or teacher pour hot water into containers 4 hours before the beginning of
class. Students measure temperature during class.
• Students pour the hot water into containers during class. A designated student or teacher checks and
records the temperature 4 hours later.
• Students or a few designated students come back at lunch or after school to check and record
temperature.
• Modify the activity. Have students check and record the temperature after one full class. The
disadvantage here is that the hot water may not have sufficiently cooled. This should be a last resort.
Implementing the Activity
• The need for two jars per group may dictate group size. Consider having one common control jar for
the class.
• You may want to limit the amount of each material available to each group. Otherwise, students may
make containers the size of pillows! You can control size by adding design criteria such as “must fit
into a 2 L ice-cream container” or “must fit in a knapsack.”
• Students should hand in their labelled diagrams and explanations of insulation properties before
testing.
Meeting Individual Needs
ESL Learners — Vacuum bottles and insulated jugs might be unknown to students new to Canada,
especially students from warmer climates. A brief introduction to these products may be necessary.
Investigation Wrap-up
• After testing is done, have students complete the Evaluate and Extend Your Skills questions.
• Have students present their creation to the class. They should point out important features, the
materials they used and how they used them, and why the finished product is a good insulator.
• Discuss with students the advantages of the brainstorming they did at the beginning of the
investigation.
Evaluate Answers
1. and 2. Answers will vary.
Extend Your Skills Answer
3. Comparisons will vary. As students compare jars, they may find the following differences:
• amount and kind of insulation;
• some students may forget to insulate the bottom and the lid of the container; and
• some students may not use aluminum foil to reflect heat back into container.
Opinions about which insulation is best will vary. Foam is chosen by most commercial
manufacturers.
ASSESSING STUDENT LEARNING
ACTIVITY
OUTCOMES/CONCEPTS
© 2002 McGraw-Hill Ryerson Limited
ASSESSMENT OPTIONS
25
Design & Do
Investigation 6–D:
When You’re Hot ...
p. 118
– describe three ways heat is transferred
– explain technologies that reduce heat
transfer
– test the design of a constructed device
– identify and correct practical problems
in the way a constructed device
functions
– evaluate designs in terms of function
and use of materials
– Evaluate the plan for an insulated jar.
– Evaluate the finished product. Was care taken
in finishing it?
– Design and Construct a Device Checklist
– Design and Construct a Device Rubric
Reading Check Answer (p. 119)
Three ways that heat transfer is controlled in a kitchen or shop include:
• insulation wrapped around or contained inside major appliances such as stoves,
freezers, refrigerators, dishwashers, hot water tanks;
• non-metal, non-conductive handles on things that get hot;
• aprons or mitts to prevent hands and bodies from being burned; and
• foil used with soft insulation.
Section 6.2 Review (p. 119)
Key Terms Teaching Strategies
• Add these key terms to the personal study card started in Chapter 5.
• Write definitions for each key term in the Science Log or notebook.
• Write sentences that show understanding of the key terms.
Check Your Understanding Answers
1. (a) 2.04 + 3.96 = 6
(b) 7.50 + 1.25 = 8.75
(c) 2.04 + 0.19 = 2.23
2. Unlike solid wood, wood shavings trap air and take advantage of air’s high R-value.
3. Hot air rises. More insulation at the top of the house slows this heat from transferring to the outside.
4. Although aluminum is a metal and therefore conducts heat well, it is a good reflector of radiated
energy. This is why an air space surrounded with aluminum is a much better insulator than the air
space without aluminum.
5. (a) Look for ideas such as:
• Windows and doors are thinner than walls, which allows heat to transfer easily.
• Windows and doors often have cracks around them, which allows heat to escape.
• If doors are solid or windows are single-pane, there is no air space to acts as a good insulator.
(b) Answers will vary. Examples include:
• add more insulation to walls and attic
• use storm windows
• install double-glazed windows
• install insulated doors
• install weather stripping around door and windows
• cover heating ducts with foil
• wear oven mitts
• put wood or plastic handles on pots
6. Non-metals do not conduct heat. As a result, they are cooler to touch, even when the pot itself is hot.
Extension Activity
© 2002 McGraw-Hill Ryerson Limited
26
• {AB.Sc14.B.K.2.i}
Conduct a field trip to a local hardware store, lumberyard, or home insulation shop. Before the trip,
consult the planning guide for Chapter 8, Extensions for Section 8.1 in this Teacher’s Resource.
Plan the trip with the home heating expert(s) who will be conducting the tour. While discussing
your plans, listen to the person. Is this person interesting? knowledgeable? patient with questions?
Check that the facility has a number of energy-efficient products that can be shown to the
students, e.g., cutaway walls with insulation, installed storm doors, weather stripping, attic
ventilators, etc.
If a field trip is not feasible, you might have the person come in and be a guest speaker. Check
the business listings in your local telephone directory under Home Improvement and Heating
Supplies. Many of the large warehouse-type home improvement centres are equipped to conduct
seminars and classes for large groups.
ASSESSING STUDENT LEARNING
ACTIVITY
Section 6.2
pp. 111–119
© 2002 McGraw-Hill Ryerson Limited
OUTCOMES/CONCEPTS
– explain technologies that reduce
heat transfer
– describe the variation in the
ability of different substances to
absorb heat
– describe the functioning of
devices and methods that protect
against potentially dangerous heat
transfer
ASSESSMENT OPTIONS
– Ask students to list four common heat loss
areas in houses.
– Ask students to rate tested substances for their
value as insulation.
– Students complete Check Your Understanding
questions.
– Students submit answers for grading or
classroom discussion of questions to ensure
understanding.
– Science Concepts Checklist
– Science Concepts Rubric
27
6.3 Keeping Yourself Warm (p. 120)
What Students Do in Section 6.3
In this section, students:
• discover that warm clothes behave like house insulation, trapping still air;
• find out that dark clothing absorbs more heat than light-coloured clothing;
• learn how different cultures use scientific principles to stay warm and cool;
• read about activities and jobs that require special protection from extreme cold and heat; and
• plan an emergency kit to protect drivers and passengers from cold.
Science Background
Clothing insulates by holding air between fibres. The better clothes trap air, the better insulators they
are. This is why thicker clothing tends to be warmer than thinner. Thicker clothing reduces air flow and
maintains still air. Windproof material reduces or eliminates airflow through the fibres.
Students may ask why clothes need to “breathe.” Bodies give off a large amount of moisture
even when still, and more when exercising. This warm moisture gets trapped in the still air spaces
between fibres, and is a better conductor of heat than dry air. Further, if the body sweats profusely and
soaks the material, water fills or collapses the air pockets, destroying the insulation value of some
clothes. Down jackets, for example, lose their otherwise superior insulating properties when wet. The
feather structure collapses, closing all air pockets. On the other hand, wool and certain polyester
materials keep their air spaces even when wet.
On a cold day, up to 40 percent of body heat is lost through the head. Covering the head is
important for heat retention. When a person becomes overheated in winter, a hat is often the first piece
of clothing removed to cool the body and reduce perspiration.
Some students may ask about materials that “wick” moisture and repel water. Materials such as
Gore-Tex™ have very small, unevenly spaced gaps between fibres. The fibres themselves do not
absorb water. Small moisture droplets weave their way out of the material, while big drops of rain
cannot fit in.
When discussing scuba gear, students might bring up two types of suits: dry and wet. Wet suits
are used primarily in warmer conditions. These work by keeping body-warmed water close to the skin
in a tight space between the neoprene and the skin. Water can flow in and out of a wet suit. For more
comfort in cold diving conditions, a diver will use a dry suit, which keeps an insulating airspace
between the diver’s body and the neoprene.
Teaching Strategies
If you encourage students to bring in their own winter wear, be sensitive to the pressure students are
under to wear the “right” clothes. Many students do not wear name brands, or do not dress warmly,
because they cannot afford to. Nevertheless, a critique of clothes’ merits in terms of warmth is
appropriate. Starting and leading a function-versus-fashion discussion can be a positive way to deal
with this subject.
As a class, discuss Figure 6.12 on page 132 of the student textbook. In moderate climates such
as Canada, we uncover during the summer to keep cool. In very hot countries such as the one shown
here, people cover up to stay cool. Discuss the use of clothing to "shade" one's body, and how this
works to maintain a cooler temperature.
Also discuss the use of colours and materials. Many people wear pale colours on warm days
because the lighter colours reduce heat absorption. Similarly, there are certain materials, such as cotton,
that have a low rate of heat absorption (and are very breathable, so they promote heat loss by
© 2002 McGraw-Hill Ryerson Limited
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evaporative cooling). Ask students who have visited or lived in equatorial countries to share their
experiences of using clothing to deal with extreme heat.
Draw students' attention to Figure 6.10 on page 120 of the student textbook. Discuss answers to
the question in the caption. Look for suggestions such as:
• Undershirt and underwear are thick and quilted. Air is held still in the quilting to slow heat transfer.
• Similarly, air is trapped in the thick knit of the mitts and sweater.
• A windproof jacket stops air exchange. This will keep the body warm.
• A down jacket is quilted with down feathers. Down is a fluffy, hair-like feather that looks more like
the fluff from a drier than a feather. When it is dry and fluffy, down is an excellent insulator.
• Like underwear and the sweater, the jacket may also have an inner material to trap air.
• If students have learned about first aid or taken swimming or boating courses, they will know that the
head is a major area of heat loss. Hats keep heat in, but as soon as people outdoors warm up, toques
are traded for ear muffs or headbands to prevent over-heating.
BLM 6–9, What Is the Best Clothing for Warmth? provides an additional activity for students to
explore the insulating qualities of different fabrics.
The following blackline master will assist you with various activities in this section:
• BLM 6–10, Winter Survival Kit Checklist.
Meeting Individual Needs
Learning Styles/LD Learners/Visually Impaired — A hands-on look at winter clothing can be
instructive and helpful for both visual and tactile learners.
Alternative Activities
• {AB.Sc14.B.K.2.i}
Wrap a thermometer lightly in a woollen scarf. Place the wrapped thermometer and an unwrapped
thermometer in a freezer for half an hour. Compare the temperature readings of the two
thermometers. Explain the difference in temperatures.
• {AB.Sc14.B.K.2.i}{AB.Sc14.B.S.1.iii}
Have students work on a project where they design “the ultimate winter jacket.” What qualities would
need to be incorporated into their jacket design?
• {AB.Sc14.B.K.2.i}{AB.Sc14.B.S.3.i}{AB.Sc14.B.S.3.iii}
Students can use the library and Internet to research types of high-tech winter clothing: Gore-Tex™
breathable fabric, windproof fabric, polyester fleece, polyester socks and underwear, or clothing made
of other special materials.
Suggest that students contact outdoor outfitting stores for information and free literature about
what goes into making each type of material and fabric.
• {AB.Sc14.B.K.2.ii}
Invite a firefighter to the class to show students the suit worn while fighting fires and to explain the
many devices used to protect firefighters from heat.
Reading Check Answer (p. 120)
The diagram should show a layer of down quilted between an outer shell and an
inner lining. Students should point out the insulating air space trapped among the
fluffed-up down.
Try This! (p. 120)
Carefully select the materials students examine. Some synthetic materials have very few air spaces, but
some polyester materials claim to be as warm as wool. Have students examine these materials and find
the air spaces. If possible, include a look at down feathers as well.
© 2002 McGraw-Hill Ryerson Limited
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Reading Check Answer (p. 120)
Wool is a good insulator because it traps still, warm air in its fibres.
Reading Check Answer (p. 121)
Inuit clothing keeps the wearer warm in the following ways:
• An inner suit (fur next to the skin) combined with an outer suit (fur facing out)
transfers moisture away from the body.
• The hollow hairs of caribou fur trap air, providing insulation.
• The hood traps air so it is warmed before being breathed.
• The edge of the hood is trimmed with fur to prevent condensation.
• Waterproof seal skin is used for boots.
• Up to four layers are worn on the feet.
Did You Know? (p. 121)
Motorcyclists (and snowmobile riders) loose heat through convection (as air passes them), conduction
(as their suit absorbs body heat), and radiation (as heat radiates from their suited body to the air
surrounding them). Students may be more familiar with this (more common) heater technology as it is
used to warm snowmobile suits.
Did You Know? (p. 121)
When people work or play outside, they develop tips for warming hands and feet. Large jackets allow
hands and arms to be warmed inside the sleeves. In addition, the armpit and groin areas provide good
places to warm cold hands and feet — your own or another’s. Blowing on hands warms them for only a
short time. Ask students why this is so. Condensed moisture makes the hands colder than they were
before.
Internet Connect (p. 121)
{A.B.Sc14.B.K.2.i}{AB.Sc14.B.K.2.ii}{AB.Sc14.B.S.3.iii}
{AB.Sc14.B.S.3.vi}{AB.Sc14.B.S.4.ii}{AB.Sc14.D.K.2.i}{AB.Sc14.D.S.2.iv}
Students have an opportunity to compare modern winter clothing to that traditionally worn by the Inuit.
The Internet Connect supports and reinforces the information in Section 6.3, Keeping Yourself Warm.
You may wish to use the Internet Connect Checklist or Internet Connect Rubric while
working with this material.
Purpose
Students:
• describe the environmental conditions in Canada’s Arctic region;
• describe the Inuit and the region they inhabit;
• explain how modern winter clothing keeps people warm; and
• explain how traditional clothing keeps people warm.
Advance Preparation
WHEN TO BEGIN
1 week before
1 day before
WHAT TO DO
• Book computer lab.
• Make sure that Internet browsing software in your computer lab has the plug-ins to access
the necessary web site(s).
• Check that the suggested links are operational.
• Determine if you want students to complete ICT 6–1, Surviving in the Arctic.
© 2002 McGraw-Hill Ryerson Limited
30
APPARATUS
• multimedia computers — with sound and/or headphones
MATERIALS
ICT 6–1, Surviving in the Arctic
Time Required
• 60 minutes (less if students work in groups)
Hints and Helps
• This Internet Connect requires students to go to a number of web sites and access seven separate web
pages. Ask students to complete this activity in their Science Log or notebook. Alternatively, students
can use a word processor to input their answers electronically.
• Option: Group students into teams of four. Have individuals access the information on one of the web
pages and answer the appropriate questions. Students compile the information and share it with the
other members of their team.
Teaching Strategies
ICT 6–1, Surviving in the Arctic can be used to introduce or support the information in Section 6.3,
Keeping Yourself Warm. ICT 6–1, Surviving in the Arctic can be used in conjunction with BLM 6–
9, What Is the Best Clothing for Warmth?
Students should be instructed to complete the four parts of ICT 6–1, Surviving in the Arctic.
Part 1 introduces students to the weather and climate of the Arctic. This will be important to students
who are new to Canada and may not be aware of the harsh conditions found in this part of the world.
Part 2 focusses students on modern clothing that they might wear if they were hiking or climbing in the
mountains of Alberta. It introduces a number of terms associated with winter clothing. Part 3
establishes the link to the Inuit people. Part 4 outlines the traditional clothing worn by the Inuit and how
it helps this group of people survive in the harsh Arctic climate.
If multimedia computers with Internet access are in short supply, you might want to incorporate
this Internet Connect as one component of a Human Survival Centre. Some students can complete ICT
6–1, Surviving in the Arctic while others do the investigations and activities in the student textbook.
Meeting Individual Needs
Learning Styles — Encourage the participation of all group members.
LD Learners — Pair students who have difficulty with students who do not. Students with learning
problems might need more time to complete the activity. Arrange for these students to spend more time
at noon or after school hours.
Activity Wrap-up
• Have students create a summary chart or concept map of their findings.
• If you have used the optional group work activity, your students should share the results of their
individual research with other members of their team.
Design & Do Investigation 6–E (p. 122)
A Winter Survival Car Kit
Purpose
• Students plan, build, and critique a winter survival car kit.
Advance Preparation
WHEN TO BEGIN
WHAT TO DO
© 2002 McGraw-Hill Ryerson Limited
31
1 week before
• Consider buying or borrowing a commercially prepared roadside emergency kit.
• Bring your own emergency kit up to date for demonstration to the class.
• Purchase or collect a container that you show to students as being the maximum possible size
for the kit.
APPARATUS
MATERIALS
BLM 6–10, Winter Survival Kit Checklist
Time Required
• 60 minutes
Hints and Helps
• Restrict the size of the containers. You could designate a larger container into which the student kits
must fit, much like the method used at airports to restrict the size of carry-on luggage.
Teaching Strategies
The driver of the stuck pickup in the cartoon has some problems. If it is appropriate for your students,
you might add that the driver could have even more trouble if he were to smoke or drink. These
activities dilate blood vessels and make the body lose heat faster still.
Point out that the truck engine can be counted on to keep everyone warm for only a short time.
If the front of the truck is full of snow, the engine will overheat quickly. The truck will run out of gas
before long. In addition, running engines in parked vehicles can poison the people inside with carbon
monoxide.
Discuss what the driver should do, such as:
• Monitor himself as he digs out the truck. Make sure he stays cool and does not sweat too much.
• Close the doors and windows of the truck, unless the engine is running. If the engine is running, make
sure the windows are open a bit to prevent carbon monoxide poisoning.
• Dress properly for the weather and for this job.
• If digging snow warms him up, put the jacket aside until he needs it.
• Stay dry.
• Work on a way to get water to drink. (The engine is warm; use it to melt snow.)
Some students and their families may not own or operate a car. Even those who do may not be
familiar with what could go wrong on a winter road. Before the class considers what should go into the
kit, brainstorm what possible problems might require a winter emergency car kit. Points to cover in the
discussion include:
• weather conditions that would stop a car;
• reasons they might be driving on a remote road;
• how long drivers in the past have gone without help; and
• temperatures they might have to deal with.
Implementing the Activity
• Have students use BLM 6–10, Winter Survival Kit Checklist to compile their kits.
• Explain that some things should already be in a vehicle in winter; these do not need to be listed as part
of the emergency kit. These items would include:
– windshield scraper
– snow shovel
– battery booster cables
– sand
– first-aid kit
© 2002 McGraw-Hill Ryerson Limited
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If tools and auto equipment are to be listed, so should the knowledge of how to use them. This
may be a good time to mention the dangers involved in boosting car batteries and review the proper
procedure, if time permits.
• Once the list is compiled, students should plan to bring in the gear for the next class. It might be a
good idea to have students exchange phone numbers and remind each other to bring the needed
supplies.
• Students can have fun with this activity by putting in some small unnecessary items such as a deck of
cards, harmonica or recorder, comic or crossword books, etc.
Investigation Wrap-up
• Have students present their kit to the class, explaining each item and why it is essential.
Extension Activity
• {AB.Sc14.B.K.2.i}{AB.Sc14.B.S.3.v}{AB.Sc14.B.S.3.vi}
Test the groups with a scenario. Present a situation. The group has 10 minutes to plan an explanation
of how their kit will handle the situation. If Survivor-type programs are still popular with your
students, you might use those to motivate. However, try to use situations that really do happen.
Possible situations to use:
– a flat tire and the jack does not work
– car skidded into a snow bank and is now stuck
– car is stuck on ice without traction
– a small accident, the car will not go, one passenger has a bad cut, need to warm snow for water,
need to keep injured person warm
– stuck on a deserted road for the night, need to stay warm until the plough gets to you in the morning
Evaluate Answers
1. Socks, mitts, sweaters, and a hat are most important to keep extremities and body core warm.
2. As a minimum, one warm coat per person is needed.
3. Insulators include down clothing, sweaters, socks, etc. Windproof clothing includes nylon shell, etc.
4. The kit should contain some dried fruit, granola bars, dry soup mix, nuts (unless allergic), chocolate,
etc.
5. Candles generate enough heat to melt snow in a can. Many people put a small camping stove in their
car for the winter. Note: Survival pamphlets sometimes mention using the water in an engine for
emergency drinking water. Caution students that in Canada, engine coolant in winter is poisonous.
They should not let anyone drink it, even in an emergency. Also, they should not run the engine for
long periods to keep warm. The carbon monoxide in the exhaust would kill them faster than cold.
ASSESSING STUDENT LEARNING
ACTIVITY
Design & Do
Investigation 6–E: A
Winter Survival Car Kit
p. 122
OUTCOMES/CONCEPTS
– explain technologies that reduce heat
transfer
– describe how devices and methods that
protect against potentially dangerous
heat transfer function
– identify questions to investigate arising
from practical problems
– evaluate designs in terms of function
and materials used
© 2002 McGraw-Hill Ryerson Limited
ASSESSMENT OPTIONS
– Assess with students whether the kit looks
after the basic needs: stay warm, stay dry,
maintain body fluids. In the short term, food is
handy but not imperative for most people.
– Discuss with students the ways in which
working collegially toward a decision was:
– faster that voting;
– more satisfying than voting.
– Scientific Communication Checklist
– Scientific Communication Rubric
– Internet Connect Checklist
– Internet Connect Rubric
– Scientific Concepts Checklist
33
– Scientific Concepts Rubric
Try This! (p. 122)
Students may be surprised how warm a plastic sheet will keep them. Ask them why they think it is
effective.
• Plastic is windproof.
• To a small extent, plastic reflects heat back inside.
• To a very small extent, plastic insulates.
Internet Connect (p. 122)
{AB.Sc14.B.K.2.i}{AB.SC14.B.K.2.ii}{AB.Sc14.B.S.2.iii}
{AB.Sc14.B.S.4.ii}
In this Internet Connect, students learn what the Canadian Automobile Association recommends for an
emergency survival kit. Students can use this information to assist them with Design & Do
Investigation 6–E: A Winter Survival Car Kit. The multimedia master also asks the students to relate
different items in the survival kit to preventing the transfer of heat.
You may wish to use the Internet Connect Checklist or Internet Connect Rubric while
working with this material.
Purpose
Students:
• identify the items recommended for a winter survival kit;
• identify the items in the kit designed to prevent the transfer of heat; and
• describe how specific clothing prevents the transfer of heat by conduction, convection, or radiation.
Advance Preparation
WHEN TO BEGIN
1 week before
1 day before
WHAT TO DO
• Book computer lab.
• Make sure that Internet browsing software in your computer lab has the plug-ins to access the
necessary web site(s).
• Check that the suggested links are is operational.
• Determine if you want students to complete ICT 6–2, Emergency Survival Kit.
APPARATUS
• multimedia computers — with sound and/or headphones
MATERIALS
ICT 6–2, Emergency Survival Kit
Time Required
• 20–30 minutes
Hints and Helps
• This Internet Connect requires students to go through the Canadian Automobile Association web site.
Students remain on the Canadian Automobile Association web site for the duration of this activity.
• Advise students to complete this activity in their Science Log or notebook. Alternatively, students can
use a word processor to input their answers electronically.
• Option: Your students might be interested to see how much each item in a survival kit costs.
Hardware stores, various Internet sites, and mail order catalogues will all have these types of
materials. Ask your students to prepare an itemized budget for putting together an emergency kit.
Teaching Strategies
© 2002 McGraw-Hill Ryerson Limited
34
This Internet Connect supports the information presented in Section 6.3, Keeping Yourself Warm. In
addition, this Internet Connect links specific items in the emergency kit to the principles of heat transfer
presented in the student textbook.
The activity and ICT 6–2, Emergency Survival Kit can be used as an introduction to Design &
Do Investigation 6–E: A Winter Survival Car Kit. ICT 6–2, Emergency Survival Kit could also be
used in conjunction with BLM 6–9, What Is the Best Clothing for Warmth?
If multimedia computers with Internet access are in short supply, you might want to incorporate
this Internet Connect as one component of a Heat and Temperature Centre. Some students can complete
ICT 6–2, Emergency Survival Kit while others do the investigations and activities in the student
textbook.
Meeting Individual Needs
Learning Styles — Encourage the participation of all group members.
LD Learners — Pair students who have difficulty with students who do not. Students with learning
problems might need more time to complete the activity. Arrange for these students to spend more time
at noon or after school hours.
Activity Wrap-up
• Have students create a summary chart or concept map of their findings.
• Students can prepare and present a budget describing how much each item in the emergency kit costs.
Reading Check Answer (p. 123)
The thick, quilted material slows the transfer (conduction) of heat from the pan to
your hand. Some mitts also incorporate a foil material to prevent some radiation as
well.
Find Out Activity (p. 123)
Is Heat Transfer a Black and White Issue?
Purpose
• Students learn that dark clothes absorb more thermal energy than light clothes do.
Advance Preparation
WHEN TO BEGIN
1 week before
1 day before
WHAT TO DO
• Determine how many pairs of socks will be needed.
• Ask students to bring in socks. Socks should be of the same type, type of fabric, and thickness.
Socks should be opposite in colour: one dark, one light.
• Assemble equipment in classroom.
APPARATUS
• 2 thermometers
• tray
• heat lamp (optional)
MATERIALS
• 2 socks of the same thickness, knit, and material; one black and one white.
Time Required
• 30 minutes
Safety Precaution
• Handle the thermometers with care.
© 2002 McGraw-Hill Ryerson Limited
35
Teaching Strategies
Have students work in pairs or small groups. If necessary, organize the partners to achieve effective
working relationships. The number of thermometers available will likely be the determining factor for
group size. If you have enough thermometers, make the group size as small as possible.
Remind students that all aspects of the socks, except colour, should be the same. If you cannot
find socks of the same thickness (black socks tend to be thinner) consider using folded black and white
fabric. Use old T-shirts or rags, or look for suitable material in the remnant bin at a fabric store.
Implementing the Activity
• Students should make sure the sunlight hits both socks equally.
• If the activity is performed on a cloudy day, or if a sunny location is not available, set up a heat lamp
in the classroom for the heat source. Caution students not to touch the lamp once you have set it up.
Also, warn students not to get the socks (or their own clothing) too close to the heat lamp.
Activity Wrap-up
• Students should make brief notes about what they did and how the temperature changed.
• Have students complete the What Did You Find Out? questions.
• After discussing their answers, pose the following scenario:
You are interested in buying a tent. You plan to use it in the Rocky Mountains, where weather
changes rapidly. What colour of tent should you buy if:
– you want to ensure the tent will dry out quickly in the sunlight after a rain? a dark-coloured tent
– you want to use the tent during the daytime and hate being uncomfortably hot? a light-coloured tent
– you want to be able to hang wet clothes inside to dry when it rains? a dark-coloured tent
What Did You Find Out? Answers
1. No. The temperature of the black sock was higher.
2. The black sock absorbed heat faster.
3. The black sock would be hotter on a hot, sunny day.
4. White socks. They would be cooler for your feet.
5. Light-coloured clothes would be cooler to wear in the Sun. They absorb heat less quickly than darkcoloured clothes.
ASSESSING STUDENT LEARNING
ACTIVITY
Find Out Activity:
Is Heat Transfer a Black
and White Issue?
p. 123
OUTCOMES/CONCEPTS
– explain technologies that reduce heat
transfer
– identify questions to investigate arising
from practical problems
– use instruments for collecting data
– identify and evaluate potential
applications of findings
– evaluate designs in terms of function
and use of materials
ASSESSMENT OPTIONS
– Assess the care taken to set socks equally
under the heat source.
– Assess if students understand that the principle
is universal with these situations:
– black cars heat quickly in sunshine; and
– light-coloured roads and concrete are cooler
to walk on than black ones.
– Scientific Concepts Checklist
– Scientific Concepts Rubric
– Lab Report Checklist
– Lab Report Rubric
Reading Check Answer (p. 124)
Their suits are made of special material, which may contain flame-retardant
chemicals. The fabric chars but does not burn. Material inside the suit absorbs
moisture, keeping the firefighter cool.
© 2002 McGraw-Hill Ryerson Limited
36
Off the Wall (p. 124)
Any fire creates convection currents in the air around it. Large, very hot fires create huge updrafts;
strong winds are caused by air rushing to fill the space vacated by the hot, rising air.
Did You Know? (p. 125)
As students finish this section on protective clothing, ask them about protective clothing besides dive
suits. For example:
• Race car drivers wear special suits in case their vehicle catches fire.
• Special suits protect astronauts when they walk in space. What is the astronaut being protected from,
besides heat and cold?
• Movie stunt men and women also wear protective clothing for some stunts.
Section 6.3 Review (p. 125)
Check Your Understanding Answers
1. Answers will vary. Examples could include:
• layered clothes so one or two layers can be removed when the body warms
• insulated boots with wool socks to absorb perspiration
• windproof pants with long underwear underneath
• undershirt, fleece jacket, and windbreaker shell
• undershirt, sweater, and parka
• scarf to cover face and close neck opening
• mitts (not gloves,) so fingers and thumb can warm each other
• toque that can be put in a pocket as you warm up
2. A diver should wear:
• a wet or dry neoprene suit, depending on how cold the water is,
• neoprene gloves and booties, and
• a neoprene hood (if not wearing a dry suit).
3. Students should choose any material that was mentioned in class, such as:
• Wool would insulate body heat.
• Polyester fleece would insulate body heat.
• Windproof material stops heat transfer.
• Some modern materials claim to shed outside moisture and wick body moisture to the outside.
• Down, when dry, is a good insulator for body heat.
4. Any three of the following:
• Fur is worn next to the body to trap warm air.
• The skin of the pelt breathes moisture to the outside.
• Caribou fur as a top layer is worn with the fur facing out. Air is trapped between and inside the fur.
• A hood keeps the head and face warm.
• The parka hood is edged with wolverine or wolf fur, which do not allow ice from condensation to
collect.
• The parka is big enough that wearers can bring their arms inside the torso space to get warm.
• Feet are kept warm using up to four layers of footwear, with waterproof sealskin boots outermost.
• Similarly, mitts are made of layers of caribou pelt.
5. People need head coverings in cold climates because we lose up to 40 percent of our heat through
our head. In warm climates, a head covering helps reflect the Sun’s heat away from the head.
© 2002 McGraw-Hill Ryerson Limited
37
6. In Alberta, it would not differ that much. In both winter and summer, clothing is needed in order to
stay warm and dry in adverse conditions. A full water jug, insect repellent, and an umbrella would be
good additions. You would not need extra weight or sand for traction. You would not have to worry
about food being spoiled by freezing (but could not use canned foods); however, some foods could
spoil in extreme heat.
Extensions for Section 6.3
• {A.B.Sc14.B.K.2.i}{A.B.Sc14.B.S.2.iii}{AB.Sc14.B.S.2.ii}{AB.Sc14.B.S.3.i}
Students may use BLM 6–9, What Is the Best Clothing for Warmth? to investigate how some
clothes keep them warmer than others.
If students need to review how to use a microscope, have them check the Microscope applet in
their student CD-ROM.
Remind students to wear safety glasses and an apron when working with hot water. Caution
them to be careful when working with a kettle.
Prepare a class chart similar to Figure 6.4. A member of each group can fill in the temperatures
in the appropriate places.
Figure 6.4 Material Temperature Table
Material
1
5
Number of Minutes Since Bottle Was Filled
10
15
20
25
30
cotton
wool
fleece
nylon
control
wet cotton
wet wool
wet fleece
wet nylon
wet control
• {AB.Sc14.B.K.2.ii}{AB.Sc14.B.S.3.v}
Borrow Children of the North by Fred Bruemmer (Optimum Publishing Company Limited, ©1979 —
ISBN 0-88890-095-3) and read “A Vanishing Way of Life.” The two pages describe how children in
Lapland were raised and how the author, a man who trusted modern clothing technology, was treated
like a child by Lapland Aboriginal people and taught a lesson about the value of traditional clothing.
Providing some insight into another culture’s way of raising children, this might be appropriate
“teaching across the curriculum” material. You might discuss the following aspects of the story:
1. Describe how the children in the story were raised.
They were left on their own, never scolded.
2. How is this different from what the author is used to?
The author is used to seeing children scolded, reproached, and beaten.
3. How did the author respond to Nils criticizing his clothes?
The author ignored Nils’ suggestions. He thought his clothes were acceptable for the weather.
4. How did Nils and his friends deal with the author’s rejection of their offer of help?
They went on with their own work. Since he had refused their offer of warm clothes, they let him
trot alongside the sleigh all day as he tried to keep warm.
5. How was the author treated like a child?
They let him have his way. They let him suffer. They teased him. But they would not let him hurt
himself.
6. How do you know the author’s clothes are not good enough for the weather?
© 2002 McGraw-Hill Ryerson Limited
38
He had to stay moving to keep warm while the others sat on the sleigh.
7. How would the clothes supplied by Nils have been superior to the author’s winter clothes?
Probably the author had cotton or wool natural fibres. The new clothes would have been like Inuit
clothing — but, given the locale, made from reindeer (caribou) fur and skin.
ASSESSING STUDENT LEARNING
ACTIVITY
Section 6.3
pp. 120–125
OUTCOMES/CONCEPTS
– explain technologies that reduce heat
transfer
– describe how devices and methods that
protect against potentially dangerous
heat transfer function
© 2002 McGraw-Hill Ryerson Limited
ASSESSMENT OPTIONS
– Students complete Check Your
Understanding questions.
– Students submit answers for grading or
classroom discussion of questions to ensure
understanding.
– Science Concepts Checklist
– Science Concepts Rubric–
39
Chapter 6 Review (p. 126)
Key Terms Teaching Strategies
Have students complete some or all of the following activities to help them learn and remember the key
terms:
• Write definitions for these terms in a Science Log or notebook.
• Write each word in a sentence that shows understanding of the meaning.
• If students have used personal study cards as a memory aid, update the deck started in Chapter 5. Use
the cards to check that the words are memorized.
Students may also use Chapter at a Glance and Prepare Your Own Summary to help them review
their understanding of the ideas in this chapter.
Reviewing Key Terms Answers
1. Sentences will vary. Examples might be similar to the following.
(a) The cold metal spoon absorbs heat.
(b) Since hot chocolate is mostly water, water’s specific heat capacity will keep the hot chocolate
warm for a long time.
(c) A foam cup provides good insulation to keep the hot chocolate warm.
(d) The foam of the cup has a high R-value so it will keep the hot chocolate warm.
(e) A vacuum bottle is a better insulator than the foam cup because it has a partial vacuum and is
lined with silver paint.
Understanding Key Ideas Answers
2. (a) Substance X would be placed near the top.
(b) Substance Y would be placed near the bottom.
3. Copper will heat quicker. Copper has a lower specific heat capacity than iron.
4. Hollow hair. It traps still air, which is a good insulator.
5. Mittens. There is more air space around the fingers, which work together to warm the communal air
space. Gloves usually fit more snugly than mitts; the fingers are individually encased and there is
little air space around each one.
Developing Skills Answers
6. Yes. Spilling the water means the water used for the investigation has a different mass. The student
is trying to find the number of joules per gram degrees Celsius, but the number of grams of water has
changed because of the spill and the student does not know by how much.
7. The cup with the greater amount of hot chocolate will stay warm twice as long. The cup that is half
full has twice the hot chocolate and therefore twice the thermal energy to release.
Problem Solving/Applying Answers
8. The cup with the metal spoon will cool faster. The metal is a good thermal conductor. The spoon will
help get rid of thermal energy. The other cup only loses heat through the side and out the top of the
cup.
9. The final temperatures might not be the same for some of the following reasons.
• The objects may be different substances with different heat capacities.
• The objects may have a different mass.
• The objects may not have been at the same initial temperature.
© 2002 McGraw-Hill Ryerson Limited
40
• One object may be resting on a substance that is a better conductor than the substance the other
object is resting on.
• Convection currents to one object may be blocked.
10. No. When insulation is packed tightly, the amount of space that air can occupy is decreased. This
decrease in air space will reduce the insulation’s R-value.
11. Fluffing feathers increases the size and number of air spaces around the bird. This fluffing increases
the insulation value of the bird’s feathers, and thus less heat is transferred to the outside.
Critical Thinking Answers
12. Low specific heat capacity is an advantage. Mercury, with a low specific heat capacity, warms and
expands quickly.
13. Hydrogen would be able to absorb a lot of thermal energy so, like water, it would be a good cooling
agent.
14. Edmonton has no oceans or large lakes near it. Amsterdam is close to the North Sea, which
modifies its climate.
15. Water will take a long time to cool because of its high specific heat capacity. If the frost is not too
severe, the water and the plants will remain unfrozen. Without the spray, the plants might freeze.
Blankets work by trapping warm air, thereby acting as an insulator.
16. Most of these suits are thick with insulation and covered on the outside with some type of
aluminum foil material.
Pause & Reflect (p. 127)
1. Discuss answers to the Getting Ready questions with the class. Students should be encouraged to
discuss differences between what they knew before and what they know now. Have them create a list
of all the things they did not know about keeping warm that they know now. Ask students to also list
things that are contrary to what they believed before (e.g., you cannot “let cold in,” water can be
boiled in a paper cup, etc.).
2. If you have not done this previously, discuss the role that fashion plays in selecting warm clothes, or
review it for emphasis.
Chapter at a Glance
{AB.Sc14.B.K.1.iv}{AB.Sc14.B.K.1.v}{AB.Sc14.B.K.2.i}{AB.Sc14.B.K.2.ii}{AB.Sc14.B.K.2.iii}
{AB.Sc14.B.S.1.i}
Have students use the following guideline to review the chapter. This review can be done before or
after the Chapter Review.
1. What is meant by specific heat capacity? In your answer, include whether specific heat capacity is
different for different substances. Does specific heat capacity change as a substance gets colder or
hotter? (6.1)
Answer: Specific heat capacity measures a substance’s ability to gain or lose thermal energy. Each
substance has a unique specific heat capacity. Specific heat capacity is the same whether a substance
is cold or hot.
2. Why does sand heat and cool much faster than water? (6.1)
Answer: Sand has a much lower specific heat capacity than water. This means it takes less heat to
warm sand.
3. Use specific heat capacity to explain why oceans and other large bodies of water moderate land
temperatures. (6.1)
© 2002 McGraw-Hill Ryerson Limited
41
Answer: Water has a very high specific heat capacity. Large bodies of water absorb or give off much
thermal energy to change their temperature a little. When the water is warmer than the surrounding
area, it helps warm that cool area by releasing heat. When it is hot outside, water can absorb excess
heat, cooling the same area.
4. Identify two ways that insulation works. Explain how each way slows heat transfer. (6.2)
Answer: Insulation slows heat transfer by being a poor conductor of heat or by reflecting heat. Some
insulators are poor conductors of heat, some hold pockets of still air, and some reflect heat.
5. What is R-value? What does it mean when it is higher? (6.2)
Answer: R-value measures how well an insulator slows heat transfer. The higher the number, the
better the insulator.
6. List five ways a home keeps its heat inside during the winter. As you answer this question, consider
how each of the three methods of heat transfer is slowed. (6.2)
Answer: Answers will vary, and may include the following:
• homes have foam insulation in walls of floors
• homes have fibreglass or other bat insulation in walls and ceilings
• attics have sprayed or poured insulation
• walls are lined with a reflective coating or foil
• outside doorways have storm doors or insulated doors
• windows are made of double or triple panes of glass
• windows are sealed in winter with a plastic sheet
• the outside of the house is covered with a windproof layer
• the inside of the outside wall has a vapour barrier
Most insulation slows conduction; some methods, such as sealing drafts, slow convection;
others (such as special glass) slow radiation.
7. Explain how a vacuum bottle prevents heat loss through
(a) conduction
(b) convection
(c) radiation (6.2)
Answer: (a) conduction:
• outside of the bottle is covered with plastic
• material inside conducts heat slowly
• inside container touches in a few spots
(b) convection:
• a partial vacuum prevents air movement inside the container
(c) radiation:
• inside surface is a reflective coat
8. List two ways heat transfer could be minimized when picking up a hot pan. (6.2)
Answer: Answers might include:
• lift the pan with oven mitts
• use a pan with an insulated handle
• slide the pan onto a tray and carry the tray
9. Describe ways that your winter clothing keeps you warm. (6.3)
© 2002 McGraw-Hill Ryerson Limited
42
Answer: Trapped air in clothing slows heat transfer from your body. Windproof outside covering
prevents cold outside air from being exchanged with warm air close to your body.
10. List three ways that their traditional clothing keeps Inuit people warm in winter. (6.3)
Answer: Answers will vary, but should include three (3) of:
• A fur suit (pants, parka, mitts, and boots) is worn fur side in to absorb moisture and provide
insulation.
• A second, outer parka layer blocks outside air from cooling off the trapped warm air.
• Parkas are large so arms can be kept inside to stay warm.
• Hoods lined with wolf skin prevent moisture buildup.
• Hoods allow air to be warmed, protecting lungs from cold air.
• Boots are waterproof.
11. List five things that should go into an emergency road kit. (6.3)
Answer: Five of the following should be on the list:
• shovel
• mitts
• sweater
• warm jacket or parka
• emergency flare
• blanket
• booster cables
• extra socks
• knife with can opener
• toque or warm hat
• flashlight
• reflective “help me” sign
• candles
• aluminum pot or pan
• dried food
• first-aid kit
• sand
• small tool kit
• cell phone with battery charger
12. How do people in desert climates stay cool? (6.3)
Answer: They wear light-coloured clothing to reflect heat and allow body heat to escape. Long
sleeves and robes or pants protect them from the Sun’s rays.
13. What colour fabric is warmer? (6.3)
Answer: Black fabric is warmer than light-coloured fabric.
14. How do firefighters and scuba divers protect themselves from extreme temperatures? (6.3)
Answer: Firefighters have a thick suit made of flame-retardant, insulating material. Scuba divers
have neoprene wet or dry suits, which trap warmed water or air close to the skin, thus keeping the
body warm.
Prepare Your Own Summary
{AB.Sc14.B.K.2.i}{AB.Sc14.B.K.2.ii}{AB.Sc14.B.K.2.iii}
© 2002 McGraw-Hill Ryerson Limited
43
More advanced students may find the following activities useful.
• List all the ways in which we prevent heat transfer in:
(a) buildings and homes
(b) our clothing
• Draw two pictures of a typical summer outfit and a typical winter outfit that you would wear. Use
arrows and notes to point out how each outfit is designed to protect you from heat transfer.
• List examples of clothing that protect the body from outside heat transfer on hot days. Describe how
the clothing protects from conduction, convection, and radiation. Do the same for clothing that
protects the body from losing heat due to these same three processes.
• Use your school library or the Internet to research heat transfer technology found in:
– the heat-safe suits worn by scientists studying volcanoes; or
– the protective flame-retardant gear worn by racing car drivers.
• List three things that affect how much energy it takes to heat up or cool down a substance.
• Draw a poster of a room in your home. Show all the things that protect you from extreme outside
temperatures.
ASSESSING STUDENT LEARNING
ACTIVITY
Chapter 6 Review
p. 126
OUTCOMES/CONCEPTS
– explain technologies that reduce heat
transfer
– describe how devices and methods that
protect against potentially dangerous
heat transfer function
– describe variation in the ability of
different substances to absorb heat
– describe the role of convection and
conduction in distributing heat
ASSESSMENT OPTIONS
– Have students do BLM 6–11, Chapter 6
Chapter Test. Use the results to decide what
parts of the chapter need further explanation
or practice.
– Students complete assigned Chapter Review
questions and submit answers for grading or
classroom discussion of questions to ensure
understanding.
– Science Concepts Checklist
– Science Concepts Rubric
– Science Log Checklist
– Science Log Rubric
– Scientific Communication Checklist
– Scientific Communication Rubric
Where Do We Go from Here?
In Chapter 7 students will see that, from before written history until the present, simple machines have
been and continue to be everywhere. They will measure work and investigate how simple machines
make work easy. Finally, they will evaluate the efficiency of machinery and look at some modern ideas
for living cheaply and in a more environmentally friendly way.
© 2002 McGraw-Hill Ryerson Limited
44
Answers to Chapter 6 Blackline Masters
BLM 6–1, Planning to Survive — Science Inquiry
Goal: Students use their knowledge of heat and the processes of heat transfer from Chapter 5 to help
them do and analyze Starting Point Activity: Survivor.
Answers
1. (a) aluminum foil
(b) leaves, cloth, plastic
(c) aluminum foil
2. (a) and (b) can both be addressed by using banana leaves several layers thick or woven.together.
3. It is several layers thick.
4. Braid cloth into a rope.
5. Sketches will differ, depending on individual designs. Make sure that students use materials that will
not conduct heat well.
6. Encourage student to recognize that weaving the grass might provide a useful and durable footwear.
BLM 6–2, Keeping It Cool Worksheet — Science Inquiry
Goal: Students record and analyze their data for Conduct an Investigation 6–A: Keeping It Cool.
Answers
See the section on Conduct an Investigation 6–A: Keeping It Cool in this Teachers' Resource.
BLM 6–3, Double the Water Worksheet — Science Inquiry
Goal: Students record and analyze data for Find Out Activity: Does Double the Water Take Double the
Time to Boil?
Answers
See the section on Find Out Activity: Does Double the Water Take Double the Time to Boil? in this
Teachers' Resource.
BLM 6–4, Measuring as Solids Release Heat — Science Inquiry
Goal: Students investigate whether different solids release heat at the same rate.
Answers
1. warmed most = glass marbles, warmed least = steel shot
2. most heat released = glass, least heat released = steel
3. Yes. Different materials release different amounts of heat when they start at the same temperature.
Material with a high specific heat capacity can release more heat.
4. Yes. Substances with high specific heat capacities had higher temperatures. Substances with low
numbers had lower temperatures.
BLM 6–5, Working with Specific Heat Capacity — Skill Builder
© 2002 McGraw-Hill Ryerson Limited
45
Goal: Students practise calculations using specific heat capacity.
Answers
1. One gram of water needs 4.19 J of energy to warm 1ºC.
2. (a) 5 x 4.19 = 20.95 J
(b) 12 x 4.19 = 50.28 J
(c) 8 x 4.19 = 33.52 J
3. (a) 5 x 4.19 = 20.95 J
(b) 9 x 4.19 = 37.71 J
(c) 11 x 4.19 = 46.09 J
4. (a) 4 x 0.84 = 3.36 J
(b) 3 x 0.84 = 2.52 J
(c) 15 x 0.84 = 12.6 J
5. 5 x 0.66 = 3.3
4.19
 9.28  9.3
(a)
0.45
1.97
 5.18  5.2
(b)
0.38
BLM 6–6, Working with R-value — Skill Builder
Goal: Students practise calculating R-values.
Answers
1. (a) 4.25 + 3.96 = 8.21
(b) 7.5 + 0.11 = 7.61
100
4
2. (a)
25
4 x 4.25 = 17
150
6
(b)
25
6 x 2.42 = 14.52
150
6
3.
25
6 x 1.25 = 7.5
50
2
4.
25
2 x 4.25 = 8.5
75
3
25
3 x 3.96 = 11.88
8.5 + 11.88 = 20.38
5. 25 mm solid wood = 1.25
150
6
25
6 x 4.25 = 25.5
50
2
25
© 2002 McGraw-Hill Ryerson Limited
46
2 x 7.50 = 15
1.25 + 25.5 + 15 = 41.75
BLM 6–7, Another Insulation Test — Science Inquiry
Goal: Students investigate which of the following materials is the best insulator: plastic bubble wrap,
aluminum foil, foam insulation, corrugated cardboard, or wool.
Answers
1. Foam or aluminum will likely allow the box to cool slowest. Corrugated cardboard can be expected
to let the box cool fastest.
2. Answers will vary with how well variables were controlled. You might expect the following: foam
insulation, aluminum foil, wool, bubble wrap, corrugated cardboard.
3. The first material on the list above should be first choice. Students might argue what “best” means.
This is a valid argument, as question 4 makes clear.
4. The best insulators from the investigation should be considered as first choice. Pizza envelopes are
usually lined with aluminum to reflect heat back to the pizza, and covered with a soft, light insulating
material. Rigid foam might be a good insulator but it will soon break up with use.
5. Some materials are good at preventing heat loss due to conduction; others are good for preventing
heat radiation. Materials can be combined to use their individual strengths at preventing heat loss to
make a superior insulator. Foil and a wool-like blanket are combined in a pizza envelope.
BLM 6–8, Heating the Whole Neighbourhood — Skill Builder
Goal: Students assess where many buildings lose heat.
Answers
Figure 1 — Insulate the wall. Put an aluminum foil covering on the inside.
Figure 2 — Put weather stripping on the bottom of the door.
Figure 3 — Caulk around dryer vent.
Figure 4 — Install new pane of glass.
1. See Figure 6.5 for possible answers.
Figure 6.5
•
•
•
•
Problem
single pane windows
thin doors
cracks around windows
up chimney
•
•
•
•
Possible Solution
use double glazing
use insulated doors
seal cracks around windows
put in sealable flue
BLM 6–9, What Is the Best Clothing for Warmth? — Science Inquiry
Goal: Students investigate whether there is a relationship between the type of fabric and its ability to
maintain warmth when dry and wet.
Answers
1. This will depend on the fabric chosen, but wool tends to have more air pockets than most others.
Thin synthetic fabrics tend to have the least.
2. • Cotton and, to some degree, nylon lose their shape the most.
© 2002 McGraw-Hill Ryerson Limited
47
• Fleece compacts and fills with water.
• Wool retains its shape.
3. Answers will vary depending on exact fabric chosen. One typical order would be wool, fleece,
cotton, nylon.
4. The control container should have the greatest temperature change.
5. Students should find a correlation between the amount of dead air space in the fabric and the fabric’s
ability to maintain warmth. Also, they might notice that irregularly patterned air spaces tend to be
warmer than those in a regular pattern.
6. Wool is the best for this, while cotton tends to be the worst.
7. Likely wool. It retains some of its ability to stay warm even when wet.
8. Science has little to do with the decision. Comfort, price, and aesthetics are all factors.
9. Wind cools things quickly by exchanging warmed air for cold. A windbreaker blocks this exchange.
BLM 6–10, Winter Survival Kit Checklist — Skill Builder
Goal: Students plan a winter survival kit.
Answers
Suggested items for winter survival kits could include:
Clothes — mitts, extra sweater, warm jacket, toques or warm hat, socks, sunglasses
Food — dried fruit, bouillon cubes, chocolate, salami, nuts, dry soup mix, high-energy bars
Equipment (heating, cooking, other) — candles, matches/lighter, small stove, pot or pan,
blankets, duct tape, emergency flares, knife with can opener, flashlight, reflective “help me” sign, three
quarters (for a phone), cell phone with battery charger, vice grips, stove pipe wire, cord, information
card with phone numbers of police, emergency, and parents
BLM 6–11, Chapter 6 Chapter Test — Assessment
Goal: Students write a test that assesses their understanding of the knowledge and skills learned in
Chapter 6.
You may wish to use this as a chapter test or review. For test purposes, a suggested marking
scheme (out of 56) has been provided. Feel free to adjust the marking scheme as you wish.
Answers
Multiple Choice
(1–15 = 2 marks each)
1. (b)
2. (a)
3. (d)
4. (b)
5. (d)
6. (c)
7. (a)
8. (d)
9. (b)
10. (c)
11. (d)
12. (c)
© 2002 McGraw-Hill Ryerson Limited
48
13. (c)
14. (b)
15. (b)
Short Answer
16. Look for any five (5) of the following, or other reasonable response:
• good seals around the door frames
• a rubber pad or sweep under the door
• a storm door outside to add an air space
• double-paned glass on the windows of the door
• insulation in the door’s core
• a boot room or porch before the door to act as a “buffer zone” or area of quiet air
(5 marks — 1 mark per point)
17. (a) The aluminized material reflects heat away from the wearer.
(b) radiation
(c) Accept any two reasonable answers, such as:
• vacuum bottle
• pizza carrier
• lined gloves
• oven mitts
(4 marks — 1 mark each for (a) and (b), 2 marks for (c))
Longer Answer
18. (a) Look for understanding of both of the following points.
• If they are not shivering, they are not producing heat to warm the body.
• The blanket will prevent warm surroundings from warming a person (i.e., it will insulate a
person from the outside warmth).
(b) Look for the following points:
• A blanket insulates the body and prevents warm convection currents from taking heat away.
• A blanket reflects radiant heat from the body back to the body.
(5 marks — 1 mark for each point, 1 mark for proper sentence structure)
19. See Figure 6.6 for two answers that students might suggest.
Figure 6.6 Judging Specific Heat Capacity
Procedure 1
• Heat water in a kettle to about 60ºC.
• Pour 100 mL into 2 foam cups and record
temperature with thermometers.
• Lower each block into water, one into each cup.
• Record temperatures until the temperature of the
water stops falling.
• Note which cup is now coolest.
• The coolest cup absorbed the most heat and
contains the material with the greatest specific
heat capacity.
© 2002 McGraw-Hill Ryerson Limited
Procedure 2
• Heat water in a kettle to about 60ºC.
• Pour hot water into a beaker and lower both
blocks into the beaker.
• Allow the blocks to warm for a few minutes until
the blocks and the water are at the same
temperature.
• Record temperature of water every 30 sec. When
the temperature stops dropping quickly, the three
are at the same temperature.
• Pour 100 mL of room-temperature water into 2
foam cups.
• Use tongs. At the same time, transfer each block
into the foam cups, one in each cup.
• Record temperature of the cups.
• The water that reaches the highest temperature
will have absorbed the most heat. It will have the
block with the highest specific heat capacity.
49
(12 marks — 8 marks for a procedure that: works; mentions all equipment to be used; mentions when
to record data; is specific, easy to follow, and written neatly and properly. 4 marks for a neat and
labelled diagram showing the procedure)
© 2002 McGraw-Hill Ryerson Limited
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