1. LESSON TITLE Shake, Rattle, and Stay: The Great Skyscraper Challenge 2. DRIVING QUESTION How can structural engineers design buildings to survive powerful tectonic shifts without collapsing? 3. LEARNING OBJECTIVES Students will be able to... Analyze the impact of seismic waves on various building heights and base designs. Construct a prototype structure that utilizes stabilizing techniques (e.g., cross-bracing or base isolation). Evaluate the effectiveness of their design through iterative testing on a simulated seismic shake table. 4. MATERIALS LIST(Quantities listed per group of 4 students) Item Quantity Budget-Friendly Alternative Popsicle/Craft Sticks50 sticksStrips of stiff cardboard or twigsMini Marshmallows1 bag (small)Modeling clay or play-dough ballsRubber Bands10 bandsString or twisted pipe cleanersCardboard Base1 square (6"x6")Cereal box panels or plastic lidsMasking Tape1 rollPainter's tape or glue sticksTennis Balls2 ballsCrumpled paper balls or sponges (for "Base Isolation") 5. TIMED LESSON SEQUENCE Engage (8 mins) The Jello-Earth Theory: Place a pre-made "house" of toothpicks on a tray of Jello. Shake the tray gently, then vigorously. Ask: "Why did the top floors move more than the bottom?" Show a 30-second clip of a real-world skyscraper (like Taipei 101) during a quake. Explore (20 mins) The Marshmallow Skeleton: Students build a basic 2-story cube structure using only sticks and marshmallows. They place it on their cardboard base and gently shake it side-to-side. Observe: Where does it fail first? (Usually the joints or "knees" of the building). Task: Try to make the structure 3 stories tall. Observe the "whiplash" effect on the top floor. Explain (10 mins)Direct instruction on three core concepts:Resonance: Why buildings of certain heights shake more at specific speeds.Cross-Bracing: Using triangles ($\triangle$) to distribute lateral force.Base Isolation: Decoupling the building from the ground so the earth moves, but the building stays still. Elaborate (45 mins - Main Challenge) The Seismic Survival Challenge: Groups must build a structure at least 18 inches tall that can withstand a "10-second Big One" (vigorous shaking) without losing any marshmallows. Constraint: They must incorporate at least one "Engineering Fix" discussed in the Explain phase (e.g., X-bracing or a ball-bearing base). Evaluate (7 mins) The Shake Test: Each group brings their structure to the front. The teacher (or a designated "Seismic Officer") shakes the table for 10 seconds. Students record if the building stood, swayed, or stayed. 6. DIFFERENTIATION TIERS Tier 1 (Below Level): Focus on a 1-story structure. Use tape to reinforce joints instead of just marshmallows. Tier 2 (On Level): Follow the 18-inch height requirement with at least one bracing technique. Tier 3 (Above Level): Must include a "Tuned Mass Damper" (a weighted object hanging from the top floor) and must survive a "High-Frequency" shake test. 7. DISCUSSION QUESTIONS Remember: What are the two main types of seismic waves that shake a building? Understand: Why is a triangle a stronger shape for a building frame than a square? Apply: How would you change your design if the building was being built on soft sand instead of solid rock? Analyze: Looking at the buildings that fell today, what was the most common "point of failure"? Create: How could we use recycled plastic bottles to create a "Base Isolation" system for a real house? 8. EXIT TASK The 3-2-1 Slip: Write down 3 things that make a building stable, 2 things that make it unstable, and 1 question you still have about earthquakes. 9. REFLECTION PROMPT "If you were a structural engineer in San Francisco, would you rather build a building that is extremely stiff or one that is flexible? Explain your choice using evidence from today’s shake test." 10. ASSESSMENT RUBRIC Criteria Beginning Developing Proficient Concept UnderstandingCannot identify why the building failed or how to fix it.Can identify a weakness (e.g., "it leaned") but struggles to apply STEM terms.Clearly explains use of cross-bracing or isolation to mitigate force.CollaborationOne student did all the work; others disengaged.Students shared materials but worked on separate ideas.Team roles were clear; students iterated on a single, unified design.Final ProductStructure collapsed under its own weight before the shake.Structure survived a minor shake but failed the "Big One."Structure met height requirements and survived the 10-second shake.