How can moving water contribute to physical weathering?

Question

A: it can make rocks expand and contract.
B: it can cause rocks to bump against each other
C: it can transport rocks to different locations.
D: it can cause the formation of new minerals in rocks.

Answer 1

All the listed choices can contribute to physical weathering. However, in the context of moving water's contribution to physical weathering specifically, B: it can cause rocks to bump against each other is the most direct and significant way in which moving water can contribute to physical weathering. The force of flowing water can cause particles of rock to collide with each other, resulting in the breaking apart of the rock and further weathering. The other options listed can also be secondary effects or outcomes of this primary mechanism.