Rocks changing their physical properties by Physical Weathering.
Explanation:
A geological phenomenon that changes the nature of the Rocks physically without causing any modifications in their chemical composition is termed as Physical Weathering. It may occur either in natural way or in an unnatural way.
Landslides, avalanche, volcanic eruptions, earthquake are some of the events that happens as the consequences of Natural physical weathering. When rocks are taken off by the water in a moving state they can break those rocks and sends it back to the river bed where they collide with other objects and results in its surface damage and they become rounded and smooth overtime.