Complete five-day instruction, worked examples, energy-flow reading, design briefs, misconception checks and human-scored CER rubric.
Essential question and safety
How can energy models guide better designs? Apply a complete transfer ledger and optimize under explicit criteria, related to HS-PS3-3 and HS-ETS1-2. This one-week sequence does not alone demonstrate full mastery of either performance expectation. Prior instruction: work, potential and kinetic energy, joules, watts, efficiency and closed-system conservation.
Model assumption: There is no net energy storage change in the device during the selected interval. Thus E_in=E_useful+E_thermal+E_other. Some devices store energy, and an expanded ledger would need that additional term. What counts as useful depends on the device goal.
Monday — Trace the Energy
Launch (8 minutes): Diagram a fictional motion device receiving 500 J. Ask where useful output and other transfers go and which arrow is intended performance.
Explanation (15 minutes): Sankey band widths represent quantities rather than speed. Useful 300 J, thermal 125 J, other 75 J satisfy conservation because they total 500 J.
Investigation (17 minutes): Have learners create one Sankey map from the numbers and identify a system boundary.
Exit (10 minutes): Correct the claim that thermal transfer represents vanished energy.
Demonstration: 800 J input, 480 J useful, 200 J thermal and 120 J other → 100% accounted. Useful fraction 60%, thermal 25%, other 15%. Over the same 10 s interval, corresponding mean powers are 80, 48, 20 and 12 W.
Misconceptions: Efficiency is a fraction rather than a unit of power; an energy category such as heat is only classified useful after naming the intended device function.
Student artifact: Annotated numerical audit table and a note explaining synthetic data provenance and what real measurement uncertainty would involve.
Classroom design brief: input ≤600 J, useful ≥300 J, thermal transfer ≤140 J, time ≤8 s. These thresholds are invented for mathematical reasoning, not safety codes.
Worked answers: A: 500 J, useful 60%, thermal 25%, 5 s → 300 J useful, 125 J thermal, 75 J other; passes all four. B: 500 J, useful 70%, thermal 30%, 5 s → 350 J useful, 150 J thermal; fails thermal cap. C: 650 J at useful 60%, thermal 20%, 5 s → useful 390 J but exceeds the input budget.
Focus: A design cannot pass by satisfying only the easiest criterion.
Controlled investigation: Hold input at 500 J and duration at 5 s; vary useful efficiency from 50% to 60% to 70%. At 60% useful, output=300 J. At 70%, output=350 J; a ten-percentage-point change yields +50 J.
Constraints check: When useful plus thermal fractions exceed 100%, the lab clamps thermal so its sum with useful is at most 100%. Students must note this adjustment and record the final settings, not assume a slider value that was rejected.
Portfolio: Three comparative trials, a revised candidate, saved JSON, one safe real-world test concept and a missing practical design criterion.
Claim: Accounting for where every unit of input energy goes helps identify feasible designs that satisfy several constraints.
Evidence: Compare the valid 500 J at 60% useful and 25% thermal case with the 70% useful, 30% thermal case. Require units, calculations, provenance and correct interpretation of the latter failing the thermal cap.
Correction: Improvements in one numerical metric can cause failure of another. A mathematical model cannot prove a real device safe or manufacturable.
Friday assessment: Ten randomized public open-book questions from a 20-item question bank; correction target 80%. Confidential midterm and final exams are handled through separate teacher-supervised channels.
Defines device purpose, system boundary and energy-accounting rule.
Evidence and units · 4
At least two correct computed trials with input, useful, thermal and other joules, plus power when relevant.
Sankey and conservation · 4
Flow widths and numeric table coherently represent all modeled energy pathways.
Design comparison · 4
Tests all four numerical constraints, documents trade-offs, and explains a reasoned recommendation.
Limitations and correction · 4
Distinguishes fictional values from measurements and names a real-world limitation and corrected misconception.
Teacher review threshold 16/20 = 80%. Browser practice scores are feedback only and not authoritative transcript grades.
Access pathways and enrichment
Foundation: use color-independent tables with integer energy values and fraction cards; outline all energy flows in writing. Core: compute two balanced energy ledgers and compare pass/fail constraints. Extension: derive a symbolic storage term and discuss reliability, cost, environmental impact, thermodynamics and objective-specific useful outputs.
Old khae_high_science_evidence_v1: daily journals remain unchanged. New Week 13 evidence has isolated browser-local keys and JSON export, not remote cloud sync. Dormant STOS files and authority components are not modified.