Balance (Tightrope, Gyroscopic Stabilization Backpack) | Inertia (Drag Racer)
Earthquakes! (Earthquake-Proof Structures)
Sound (Soundwave Visualization, Loudest Sounds) | Gravity (Giant Hoop Glider)
Generating Electricity (Human-Powered Generator, Wind Turbine) | Electromagnetism (Magnet Climbing)