What is an example of mechanical weathering by gravity

Abrasion

Explanation:

Mechanical weathering is generally called physical weathering where rocks are broken down physically. It means that the rocks are broken down into smaller pieces but the rocks' composition (chemically) is  not changed.

There are different ways that rocks can be broken into smaller pieces physically and gravity helps can also cause it.

Abrasion is an example of mechanical weathering where rocks bump into each other and cause the rocks to breakdown because of the force of bumping into each other. Gravity plays a role when it comes to rocks on the mountain side.

When a rock on top tumbles down the side of the mountain, it bumps into other rocks along the way. Gravity is at play here because it pulls the rock downwards, causing it to tumble.