Week 7: Week 7 Content
Grade 8 Science | Rosche | Kairos Academies
**Choose Your Path:** Select one of the following investigation pathways based on your interests: - **Path A:** [topic-specific content] - **Path B:** [topic-specific content] - **Path C:** [topic-specific content]
**Specialist Track:** As you progress, you'll develop expertise in [topic-specific content]. Advanced learners: try the extension challenge at the bottom of this page.
**Career Connection:** [topic-specific content] scientists and engineers use these skills daily in careers like [topic-specific content]. High school [topic-specific content] builds on these concepts.
**You're in Control:** Design your own investigation to answer: [topic-specific content]. Use the scientific method, but YOU decide the procedure, materials, and data collection strategy.
Accessibility & Learning Support
- Need text read aloud? Chrome: Right-click then "Read aloud"
- Need extra support? Click the green "Need help?" buttons
- Stuck? Look for the red "Stuck?" boxes
Important Tips
- Your work saves automatically in Google Forms.
- KEY CONCEPT: Energy can NEVER be created or destroyed - only transformed!
- Spiral Review: Connect to collisions (W6) and KE/PE (W5).
Why This Matters to YOU:
Every time you charge your phone, drive in a car, or turn on a light, you're using energy systems. Understanding WHY machines can't run forever helps explain everything from why cars need gas to why you need to eat!
The Phenomenon: The Perpetual Motion Fraud
Throughout history, inventors have claimed to create machines that run forever without any energy input:
- Self-spinning wheels that never stop
- Water pumps that power themselves
- Magnetic motors with "free energy"
Every single one has been proven to be a fraud or misunderstanding.
Focus Question: Why can't machines run forever without adding energy?
WORKED EXAMPLE: Data Center Energy Audit (Week 7 - Expert Transfer)
Week 7: YOU transfer mastery to completely new contexts!
PROBLEM:
A cryptocurrency mining data center uses 50,000 kWh of electrical energy daily. Of this: 35,000 kWh goes to servers (which convert electricity → computation + heat), 10,000 kWh goes to cooling systems (which remove the heat generated by servers), and 5,000 kWh goes to lighting and auxiliary systems. The servers only produce 500 kWh worth of "useful" computation; the rest becomes waste heat. Even the cooling system turns 90% of its input into more waste heat. Company claims they're "carbon neutral" because they buy renewable energy credits. Design a complete energy flow diagram and calculate the ACTUAL overall efficiency of this facility. Then propose THREE specific improvements that would reduce total energy consumption.
YOUR TURN - Novel Context Transfer:
- Identify ALL energy transformations in this multi-stage system (electrical → computational, electrical → thermal, thermal → more thermal)
- Apply conservation principles to calculate where EVERY joule of the 50,000 kWh ends up (hint: almost all becomes heat!)
- Justify your efficiency improvements using evidence about unavoidable vs. reducible energy waste
Vocabulary
Cognate Strategy: Many science words look similar in English and Spanish — use your Spanish to learn science!
| Term | Spanish | Definition |
|---|---|---|
| energy dissipation | disipación de energía | Spreading of energy into less useful forms (usually thermal) |
| thermodynamic efficiency | eficiencia termodinámica | Ratio of useful work output to total energy input in heat engines |
| heat loss | pérdida de calor | Thermal energy transferred to surroundings - unavoidable in all processes |
| energy transformation | transformación de energía | Conversion from one energy form to another (chemical → thermal → mechanical) |
| mechanical advantage | ventaja mecánica | Ratio of output force to input force - relates to energy efficiency |
| power output | — | potencia de salida |
| irreversible process | — | proceso irreversible |
| conservation | — | conservacion |
| efficiency | — | eficiencia |
| thermal energy | — | energia termica |
| friction | — | friccion |
| perpetual motion | — | movimiento perpetuo |
AUTONOMY SUPPORT: Choose Your Challenge Level for Novel Problems
Week 7 is about tackling completely new contexts. Choose the approach that matches YOUR readiness:
START WITH BASICS: Build from familiar concepts
- Focus on SINGLE energy conversions first (like the light bulb example from Station 1)
- Use the formula: Efficiency = (Useful Out / Total In) × 100% for each stage separately
- Draw simple energy flow diagrams with arrows showing input → useful output + waste
SCALE UP SLOWLY: Apply to moderate complexity
- Analyze 2-3 stage systems (like car engine → transmission → wheels) before tackling complex networks
- Calculate overall efficiency by multiplying individual stage efficiencies together
- Compare different technologies for the SAME purpose (incandescent vs LED, gasoline vs electric cars)
PUSH YOUR LIMITS: Expert-level transfer
- Design complete multi-stage energy systems with 4+ conversions and calculate end-to-end efficiency
- Integrate concepts from ALL cycle weeks (KE/PE from W5, collision momentum from W6, now conservation)
- Propose optimizations for real-world systems (buildings, vehicles, power plants) with cost-benefit analysis
Environmental Justice: Climate resilience and equitable energy access in St. Louis
Ameren Missouri & Climate Resilience
St. Louis faces increasing extreme heat events—July 2023 had 15 days over 95°F. Ameren Missouri, the regional utility, must balance energy supply (power plants) with conservation (efficiency programs) to prevent grid overload during heat waves. Dr. Katharine Hayhoe, climate scientist at The Nature Conservancy, studies how energy infrastructure must adapt to climate change. Lower-income St. Louis neighborhoods often lack resources for energy-efficient upgrades (insulation, modern HVAC), leading to higher bills and heat vulnerability. Grid engineers ($80k-$125k), renewable energy developers ($70k-$110k), and energy efficiency consultants ($55k-$85k) design resilient systems. Understanding energy conservation helps you advocate for equitable access to efficiency programs and renewable energy.
Word count: 140 words
Worked Example
Step-by-Step Problem Solving
Problem Scenario
Review the problem scenario and work through each step below.
Practice These Vocabulary Terms
Nikola Tesla: Serbian-American inventor who revolutionized energy systems through AC power transmission and efficiency optimization
Meet the Scientist: Nikola Tesla (1856-1943)
Nikola Tesla was a Serbian-American inventor and electrical engineer who revolutionized how we understand and use energy. While Thomas Edison developed direct current (DC) electricity, Tesla championed alternating current (AC), which became the foundation of modern power distribution systems worldwide.
Tesla understood energy efficiency at a level ahead of his time. He recognized that AC power could be transmitted over long distances more efficiently than DC, allowing energy to reach entire cities from centralized power plants. This insight transformed electrical engineering and made modern civilization possible—every power plant today uses AC transmission because of Tesla's work.
Beyond electricity, Tesla was obsessed with understanding energy transformation. He built the Tesla coil—a device that converts low-voltage, high-current electricity into high-voltage, low-current electricity. This invention demonstrated principles of energy conservation and resonance that scientists still study today. His work on wireless power transmission explored how energy could be transferred without physical wires.
Tesla's greatest contribution wasn't a single invention—it was his systematic approach to energy systems. He understood that every transformation of energy (electrical to mechanical, mechanical to thermal) involves efficiency losses. He designed systems to minimize these losses, laying the groundwork for modern engineering optimization.
Today, the unit of magnetic flux density is named the "tesla" in his honor. When you charge your phone or use electricity at home, you're benefiting from Tesla's innovations in AC power transmission and his understanding that energy systems must be designed for maximum efficiency.
Word count: 263 words
Why This Matters in ST. LOUIS
Hook - The Perpetual Motion Fraud
12 Points | ~10 Minutes
The Challenge
What You'll Do:
- Watch videos of "perpetual motion machine" claims
- Identify where energy is secretly being added
- Explain why 100% efficiency is impossible
COMPLETE THE HOOK FORM BELOW
[EMBED G8.C1.W7 Hook Form Here]
Station 1 - Energy System Investigation
20 Points | ~18 Minutes
Track ALL the Energy
Energy Accounting Framework:
Energy In = Energy Out (always!)
Useful Energy + Wasted Energy = Total Input
Example: Light Bulb Energy Flow
| Input | Useful Output | Wasted Output |
|---|---|---|
| 100 J electrical | 10 J light (10%) | 90 J thermal (90%) |
Need help? Click for hints
Remember:
- Energy is NEVER destroyed - track where it ALL goes
- Friction always converts motion to thermal energy
- Sound, heat, deformation = "wasted" energy
Virtual Lab: Energy Forms & Changes
Use this PhET simulation to observe how energy transforms between different forms (thermal, light, mechanical, electrical) and how some energy is always "lost" as waste heat. You'll track energy through complete systems to understand conservation and efficiency.
Investigation Steps (10-12 minutes):
- Systems Tab: Start with the "Systems" tab. Build an energy system with a burner, water, and a steam generator
- Track Energy Flow: Turn on "Energy Symbols" to see where energy goes. Watch thermal energy transfer from burner → water → steam → mechanical energy
- Measure Efficiency: Compare energy input (at burner) to energy output (mechanical work). Notice how much becomes waste heat
- Try Different Systems: Test light bulb, teakettle, and solar panel. Track what percentage of input energy becomes useful vs. wasted
- Energy Accounting: For each system, verify that Energy In = Useful Output + Waste Heat (conservation!)
- Compare Efficiencies: Which system wastes the MOST energy? Which is most efficient?
Key Questions to Consider:
- Where does the "lost" energy go in each system? (Hint: It becomes thermal energy/heat)
- Can you create a 100% efficient system? Why or why not?
- How can you calculate efficiency = (useful energy out / total energy in) × 100%?
- Why do engineers care about tracking ALL energy transformations, even "wasted" energy?
COMPLETE STATION 1 FORM BELOW
[EMBED G8.C1.W7 Station 1 Form Here]
Station 2 - Efficiency Analysis
20 Points | ~15 Minutes
Calculate System Efficiency
Efficiency Formula:
Efficiency = (Useful Energy Out / Total Energy In) x 100%
| System | Typical Efficiency | Where Energy Goes |
|---|---|---|
| Incandescent bulb | 5-10% | 90%+ to heat |
| LED bulb | 40-50% | 50-60% to heat |
| Car engine | 20-30% | 70-80% to heat |
| Electric motor | 85-95% | 5-15% to heat |
Need help? Click for calculation guide
Example: A motor uses 500 J and produces 400 J of motion.
Efficiency = (400 / 500) x 100% = 80%
Wasted = 500 - 400 = 100 J (as heat)
COMPLETE STATION 2 FORM BELOW
[EMBED G8.C1.W7 Station 2 Form Here]
Station 3 - Design an Efficient System
25 Points | ~20 Minutes
Engineering Challenge: Maximize Efficiency
Your Mission:
Design an energy system that maximizes useful output while minimizing waste. Choose from:
- Option A: Home heating system
- Option B: Transportation vehicle
- Option C: Power generation plant
Design Requirements:
- Identify ALL energy inputs and outputs
- Calculate expected efficiency
- Explain how you minimized waste
- Acknowledge what waste can't be eliminated (and why)
COMPLETE STATION 3 FORM BELOW
[EMBED G8.C1.W7 Station 3 Form Here]
Exit Ticket - Energy Conservation Integration
23 Points | ~15 Minutes
Show What You Learned
Question Types:
- 2 NEW - Energy conservation, efficiency
- 2 SPIRAL - Collisions (W6), KE/PE (W5)
- 1 INTEGRATION - Connect thermal, mechanical, and conservation
- 1 SEP - Argue why perpetual motion is impossible
COMPLETE EXIT TICKET BELOW
[EMBED G8.C1.W7 Exit Ticket Form Here]
Week 7 Summary
Conservation: Energy cannot be created or destroyed - only transformed
Efficiency: No system is 100% efficient - some energy always becomes thermal
Perpetual Motion: Impossible because friction always converts motion to heat
Enrichment & Extension
Optional deep dives for early finishers.
Optional content if you finish early or want to go deeper.
Scientist Spotlight
Research a scientist who contributed to this week's topic area and describe their key findings.
Environmental Justice Connection
Explore how this week's science concepts connect to environmental justice issues in our community.