What is a primary agent of physical weathering in nature?

Water is indeed a primary agent of physical weathering in nature, primarily through processes such as freeze-thaw cycles and abrasion. When water seeps into cracks in rocks and then freezes, it expands as it turns to ice. This expansion exerts pressure on the surrounding rock, causing it to crack further and ultimately break apart. As the ice melts, the cyclical process continues, contributing to the physical breakdown of the rock.

Additionally, water can also facilitate weathering through erosion, where it carries sediment and particles that can physically abrade surfaces, further contributing to weathering. Overall, the role of water in both freeze-thaw processes and as a primary agent for erosion and abrasion underscores its crucial contribution to physical weathering in natural environments.