In this Mystery, students compare multiple solutions for preventing erosion. In the activity, Erosion Engineering, they design and test ways to keep water from washing away a hill modeled out of cornmeal. We will make our hills out of sand instead. 1. Get Materials Damp Sand (slightly wet) Drip sticks from Mystery 3 Cups from Mystery 3 Aluminum foil Cotton balls Small Cups Plates Paper towels Toothpicks 2. Click on the to watch the and do the experiment. Complete the slides when the tells you to. IF you cannot do this experiment at home, watch the demonstration videos and answer the questions. 3. Click the to turn in your work.