Sound (Soundwave Visualization, Loudest Sounds) | Gravity (Giant Hoop Glider)
Generating Electricity (Human-Powered Generator, Wind Turbine) | Electromagnetism (Magnet Climbing)
Vibration (Vibrobot) | Hot and Cold (Dry Ice, Hot Air Balloon)
Storing Energy (Giant Spool Racer) | Moving Air (Stomp Rocket)
