may 2015 jr. chapter stem activity chillin’ out: designing an insulator
TRANSCRIPT
May 2015 Jr. Chapter STEM Activity
Chillin’ Out:Designing An Insulator
Some simple advice:
• Be prepared. Test-drive the activity beforehand.
• Have all the required materials on hand.
• Keep students on track.
• Keep an eye on the clock and follow the time frame.
• Be flexible and creative.
• Have fun!
Chillin’ Out
Goal:Students learn about different types of heat transfer and insulating properties of different types of materials. Working in teams, they design a system intended to keep a cup of water cool for an hour.
Engineering/STEM areas:Thermodynamics, materials science, product design
Learning objectives• Understand thermal conductivity and the three types of heat transfer• Assess materials as conductors or insulators• Understand how different materials can facilitate or slow heat transfer• Predict which materials in what type of design will best insulate a cup
of cold water.
Chillin’ Out
Time: 45 mins + 15 mins. Note: the activity requires that the insulated cups sit for an hour. During that time, students can do the life skills portion of the class.
Suggested group size:2-3 depending on number of studentsMaterials:• Student Resource Sheets (in lesson)• Student Worksheets (in lesson)• A pitcher or thermos with water and ice in it (enough to fill one cup per group of
students)• Paper cups (one per group of students)• Thermometer (one per group of students)• Materials to use for insulation, such as foil, cotton balls, felt, moss, cardboard,
paper, duct tape, straws, string, yarn, packing foam, styrofoam cups, sand, cloth or clothing such as socks or mittens, coffee filters, aquarium marbles, etc.
• Plastic wrap to hold the insulating materials around the paper cups
Chillin’ Out
Before the activity:
• Read through both the student and instructor resources so you have the background information
• Gather all the necessary materials.
• Make enough copies of the Student Resource so that each student has one • Make one copy of the Student Worksheet per group, plus a few extras
• Design and build your own insulating cup that you can use as a demo
• Set aside an area where students can set their cups while some time passes.
• Collect a few insulating containers that do not rely on a vacuum (i.e. not a Thermos). You could use an insulated lunch bag, stryofoam or regular foam insulators, potholders, etc.
Chillin’ Out
Background in the Student Resource
Three types of heat transferStudents learn that heat can move from one place or material to another via:• Conduction• Convection• Radiation
Conductors Students learn the properties that make some materials good heat conductors and others good insulators. They consider the differences between thermal and electrical conductivity.
Remember to read the Student Resource and Worksheet beforehand!
Chillin’ Out
Activity procedure• Pass around the insulating materials you’ve collected and ask students to consider what
they’re made of.
• Point out that these items can be used both to keep something warm and to keep it cool. Ask how that can be.
• Give students this scenario: It’s a warm spring day (hopefully it actually will be!) and they’re having a picnic. Unfortunately, they forgot a cooler or ice, and they need to devise a way to keep their drinks cold. Fortunately, there are lots of materials in their backpacks and in the environment around them. Their task is to come up with a way to insulate their drinks.
• Go over the information in the Student Resource and Worksheet, making sure students understand the three types of heat transfer and the properties of heat conductors and insulators.
• Go over the materials available to build the insulators. Give each group a cup, and allot about 10-15 minutes for students to design their cup insulators on paper. If you want students to be able to compare how different materials insulate, assign different sets of materials to different groups.
Chillin’ Out
Activity procedure (cont’d)• Next, give students about 20 minutes to build their cup insulators. They should wrap their
cups in only one or two layers of plastic wrap, to hold the insulating material together. (You may want to ask students to consider whether or not plastic is a good insulator.)
• When each group finishes their insulated cup, fill the cup with ice water and give the students a thermometer to put in the cup. Tell students to let the thermometer sit for about a minute. When the temp looks like it’s stopped going down, they should record the thermometer reading on their student worksheet.
• When all the cups are full, tell students to place them in the area you set aside for them (with the thermometers in them). Tell students the cups will sit for an hour, after which students will compare starting and ending temperatures.
• If possible, give students time to record a temperature reading halfway through the hour.
• After an hour, students should record their thermometer readings. Ask each group how much the temperature rose in their cup. Compare how the different groups’ materials and designs performed as insulators.
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Assessment
• Each group should explain:
• Why they think their insulator performed as it did, based on the properties of the materials and the types of heat transfer that occurred. They need to describe specific properties the materials must possess to have been as effective (or ineffective) as they were. Students can compare their chosen materials with their classmates’ choices or with other materials they decided not to use.
• What improvements they would make to their design and why
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Extensions• Have students research different types of housing insulation and come up with three
different insulation plans suited to three different climates.
• Discuss the way that vacuums can be used for insulation, and why they can be good insulators. Use examples such as a Thermos,
• Experiment and calculate the thermal conductivity of different materials.(http://agpa.uakron.edu/p16/lesson-print.php?id=thermal_conductivity has an interesting example with lots of background information.)
Chillin’ Out
Teaching tips• Take the reins on dividing the class into student groups (rather than letting students
decide). If you know your students, try to be sure that each group has a balance of personalities, with a mix of outgoing and more introverted students.
• Circulate around the classroom as students are working and be sure to keep them on track, answer questions, and encourage students who are less assertive.
• Some groups will be more active and will immediately dive into design, and others will be more reticent. Show groups your bridge or drawing to give them inspiration.
• Encourage students to think about different examples of insulation in their environment and in nature. How do their clothes work as insulation? How are buildings insulated? How does fur or feathers keep an animal warm?
Chillin’ Out
Takeaways:• Heat can be transferred between materials in three different ways.
An engineer designing something that’s intended to moderate temperatures needs to keep conduction, convection, and radiation in mind.
• Some materials are good thermal conductors and others are good thermal insulators. This involves different material properties than those that determine whether a material is a good electrical conductor or insulator.
• Engineers use their knowledge of the thermal properties of materials when designing products intended to control heat transferInsulators can keep objects either warm or cold, and they do so by reducing conduction, convection, and radiation.
Chillin’ Out
Resources and bibliography:
BBC “Keeping Warm” lesson planhttp://www.bbc.co.uk/schools/teachers/ks2_lessonplans/science/keeping_warm.shtml
Maine Energy Education Curriculumhttp://www.powersleuth.org/docs/EHM%20Lesson%207FT.pdf
Insulation Materials Investigationhttps://www.teachengineering.org/view_activity.php?url=collection/uoh_/activities/uoh_insulation/uoh_insulation_activity1.xml
Keep It Cool lesson planhttp://tryengineering.org/lesson-plans/keep-it-cool
