Energy, Heat & Thermal Design — Extension · Science 6: Matter, Energy & Earth Systems, Grade 6
How do energy transfers explain cooling and a feasible thermal design? Which feasible sleeve slows cooling under the matched model, and what should be redesigned?
Design and compare a cup sleeve
Investigate
Which feasible sleeve slows cooling under the matched model, and what should be redesigned?
Three 35–45-minute sessions: plan and predict; examine or collect evidence; explain, revise, and reflect. Use the complete supplied record when materials, time, access, or safe conditions are unavailable.
Materials
- Supplied repeated cooling and cost records.
- Optional matched cups with safe-fitting sleeves and thermometers chosen by a parent.
- Clean water warmed by an adult to no more than 40 °C, a timer, and tray for an approved test.
- A notebook for starting/final temperatures, controlled conditions, and a design sketch.
Before you begin
No flames, boiling water, powered heaters, or sealed heated vessels. A parent manages warm water and stable containers. The complete supplied data can replace the hands-on test.
Plan a fair design comparison
Change sleeve design while matching 100 mL water, 40 °C starting temperature, fitted lid, ten-minute interval, surroundings, and thermometer method. Desired mean drop is at most 6 °C; fictional cost limit is 5 tokens.
Method
- State the criteria and constraints before comparing the records. Predict a useful transfer mechanism to change.
- Sketch sleeves A and B and identify which pathways they might reduce. List conditions that must remain comparable.
- For an approved test, record matched starts and ten-minute readings in repeated trials. Otherwise use the complete supplied records.
- Calculate each trial’s drop, mean drop, range, and whether each design meets the cost constraint.
- Choose a feasible recommendation or propose a specific cheaper redesign that would require its own new test.
- Write a claim–evidence–reasoning explanation with a limitation and compare it with the initial prediction.
Supplied illustrative record — use when an actual test is unavailable
Illustrative classroom data authored for analysis, not measurements from a real learner, stream, product, or field study. Actual observations may differ; record them honestly and compare the methods.
| Design/trial | Start (°C) | After 10 min (°C) | Cost (tokens) |
|---|---|---|---|
| A / 1 | 40 | 35 | 4 |
| A / 2 | 40 | 34 | 4 |
| A / 3 | 40 | 35 | 4 |
| B / 1 | 40 | 37 | 7 |
| B / 2 | 40 | 36 | 7 |
| B / 3 | 40 | 37 | 7 |
Analyze and explain
- Calculate all drops and the two means, using sensible rounding.
- Which designs meet each stated criterion or constraint?
- What transfer pathways could a sleeve affect, and which remain?
- Propose a justified revision and an actual retest rather than inheriting results.
What a strong explanation includes
- Correct drops and mean comparisons with °C.
- Performance and cost both considered.
- Mechanisms and temperature/energy distinction explained.
- A specific redesign requiring new evidence.
- Actual or supplied data labeled honestly.
Parent / teacher guide: discuss after the investigation
A’s drops are 5, 6, and 5 °C, averaging about 5.3 °C. B’s are 3, 4, and 3 °C, averaging about 3.3 °C. B has a smaller modeled mean drop, but its seven-token cost exceeds the five-token constraint. A meets the stated average-performance criterion and cost limit, so it is the feasible recommendation under these supplied conditions. The records do not imply A never loses energy or always outperforms every alternative. Retain thermometer resolution, reading times, and the range beside the mean so a small apparent improvement is not treated as exact. Cooling is consistent with net heat transfer from warmer water to cooler surroundings. A sleeve can change rates through the wall and alter airflow, while a lid, radiation, and other pathways also matter. Temperature drop is a measured response, not a direct joule value. Keeping water amount, starting temperature, lids, time, and environment comparable is needed before assigning the difference to design. A cheaper B variant might reduce material or use a different layer, but that change could worsen cooling. It needs a new matched comparison; its old mean cannot be silently reused. A next test should repeat feasible designs and preserve all results, including variation. The model costs are fictional, and actual choices would require available material, fit, reuse, and safe handling evidence as well.
Compare this model with the learner’s actual evidence. Different measurements can support a different conclusion; check the reasoning and limitations, not matching wording.
Extend the chapter investigation by evaluating its evidence and proposing a better test.
Problem 1
Answer and explanation
A’s drops are 5, 6, and 5 °C, averaging about 5.3 °C. B’s are 3, 4, and 3 °C, averaging about 3.3 °C. B has a smaller modeled mean drop, but its seven-token cost exceeds the five-token constraint. A meets the stated average-performance criterion and cost limit, so it is the feasible recommendation under these supplied conditions. The records do not imply A never loses energy or always outperforms every alternative. Retain thermometer resolution, reading times, and the range beside the mean so a small apparent improvement is not treated as exact. Cooling is consistent with net heat transfer from warmer water to cooler surroundings. A sleeve can change rates through the wall and alter airflow, while a lid, radiation, and other pathways also matter. Temperature drop is a measured response, not a direct joule value. Keeping water amount, starting temperature, lids, time, and environment comparable is needed before assigning the difference to design. A cheaper B variant might reduce material or use a different layer, but that change could worsen cooling. It needs a new matched comparison; its old mean cannot be silently reused. A next test should repeat feasible designs and preserve all results, including variation. The model costs are fictional, and actual choices would require available material, fit, reuse, and safe handling evidence as well.
Problem 2
Answer and explanation
A’s drops are 5, 6, and 5 °C, averaging about 5.3 °C. B’s are 3, 4, and 3 °C, averaging about 3.3 °C. B has a smaller modeled mean drop, but its seven-token cost exceeds the five-token constraint. A meets the stated average-performance criterion and cost limit, so it is the feasible recommendation under these supplied conditions. The records do not imply A never loses energy or always outperforms every alternative. Retain thermometer resolution, reading times, and the range beside the mean so a small apparent improvement is not treated as exact. Cooling is consistent with net heat transfer from warmer water to cooler surroundings. A sleeve can change rates through the wall and alter airflow, while a lid, radiation, and other pathways also matter. Temperature drop is a measured response, not a direct joule value. Keeping water amount, starting temperature, lids, time, and environment comparable is needed before assigning the difference to design. A cheaper B variant might reduce material or use a different layer, but that change could worsen cooling. It needs a new matched comparison; its old mean cannot be silently reused. A next test should repeat feasible designs and preserve all results, including variation. The model costs are fictional, and actual choices would require available material, fit, reuse, and safe handling evidence as well.
Problem 3
Answer and explanation
A’s drops are 5, 6, and 5 °C, averaging about 5.3 °C. B’s are 3, 4, and 3 °C, averaging about 3.3 °C. B has a smaller modeled mean drop, but its seven-token cost exceeds the five-token constraint. A meets the stated average-performance criterion and cost limit, so it is the feasible recommendation under these supplied conditions. The records do not imply A never loses energy or always outperforms every alternative. Retain thermometer resolution, reading times, and the range beside the mean so a small apparent improvement is not treated as exact. Cooling is consistent with net heat transfer from warmer water to cooler surroundings. A sleeve can change rates through the wall and alter airflow, while a lid, radiation, and other pathways also matter. Temperature drop is a measured response, not a direct joule value. Keeping water amount, starting temperature, lids, time, and environment comparable is needed before assigning the difference to design. A cheaper B variant might reduce material or use a different layer, but that change could worsen cooling. It needs a new matched comparison; its old mean cannot be silently reused. A next test should repeat feasible designs and preserve all results, including variation. The model costs are fictional, and actual choices would require available material, fit, reuse, and safe handling evidence as well.
Problem 4
Answer and explanation
A’s drops are 5, 6, and 5 °C, averaging about 5.3 °C. B’s are 3, 4, and 3 °C, averaging about 3.3 °C. B has a smaller modeled mean drop, but its seven-token cost exceeds the five-token constraint. A meets the stated average-performance criterion and cost limit, so it is the feasible recommendation under these supplied conditions. The records do not imply A never loses energy or always outperforms every alternative. Retain thermometer resolution, reading times, and the range beside the mean so a small apparent improvement is not treated as exact. Cooling is consistent with net heat transfer from warmer water to cooler surroundings. A sleeve can change rates through the wall and alter airflow, while a lid, radiation, and other pathways also matter. Temperature drop is a measured response, not a direct joule value. Keeping water amount, starting temperature, lids, time, and environment comparable is needed before assigning the difference to design. A cheaper B variant might reduce material or use a different layer, but that change could worsen cooling. It needs a new matched comparison; its old mean cannot be silently reused. A next test should repeat feasible designs and preserve all results, including variation. The model costs are fictional, and actual choices would require available material, fit, reuse, and safe handling evidence as well.