Shiny rocks (or cheap decorative rocks from Walmart)
Sandpaper (one piece for each group or rotation)
Recording Sheets (for noting observations)
Bags (for putting away used rocks)
Prepare the Experiment:
Provide each group with a shiny rock (or decorative rock) and a piece of sandpaper.
Rub the Rock:
Instruct students to rub the rock gently and quickly with the sandpaper. Allow each student to take turns rubbing the rock.
Observe Changes:
Have students observe any changes in the rock’s texture or appearance as a result of rubbing with the sandpaper. Note any wear or changes in shine.
Record Observations:
Students should record their observations on the provided sheet, noting the condition of the rock before and after rubbing.
Clean Up:
After each group, ensure that the rocks are placed in a separate bag or disposed of if not needed. The sandpaper can be reused for subsequent groups.
Discussion:
Discuss with students how the rubbing simulates physical weathering, as the sandpaper acts as an abrasive force that wears down the rock’s surface. Explore how this experiment demonstrates the effects of mechanical weathering.
Reflection:
Ask students what they learned about physical weathering and how the experiment helped them understand the process of rocks being worn down through mechanical actions.