Room 8 Builds an Airport
Room 8 is building a model airport on the classroom project table. Beside the runway is a small soil slope. The builders wonder how to keep rain and wind from carrying soil onto the runway.
An adult tests three designs inside large catch trays: bare soil, soil with growing grass, and soil under a straw mat. Each model starts with 14 small scoops of soil and the same slope. Clips hold the straw mat at two corners.
For each water test, the adult pours one cup of water from the same height at the same slow speed. For wind tests, the adult uses fresh models. A hand fan stays the same distance away and makes 15 gentle strokes. Students stand back.
The class catches soil that leaves each model. After it dries, they measure it with the same small scoop. They subtract that amount from 14 to find the soil that stayed. A cover that keeps more soil in place gives better protection in that test.