Why type of physical weathering is caused by the expansion of water?

Physical weathering is caused by the change in temperature on rocks. When it effects on water, it freezes, breaking the rock.

Freeze and Thaw effect

Explanation:

Physical weathering refers to the breaking down of rocks by agents such as water, wind, and ice. Water plays an important role in the weathering of rocks. The rocks often contain crack in them. During precipitation, the water is trapped in these fractures. The water freezes and starts expanding. This increases the volume of water by 9%. As a result of which it exerts pressure causing the rock to break. This type of physical weathering process is known as the freeze and thaw effect.