The activity that the student could perform to model the physical weathering of rock is:
Place several cookies in a box, and then shake the box.
This activity simulates physical weathering, which involves the breaking down of rocks into smaller pieces through mechanical processes, similar to how rocks are weathered in nature by forces such as wind, water, and ice. The shaking of the box represents these mechanical forces acting on the cookies, causing them to crumble and break apart.