1. Frost Wedging: This process is highly effective in climates that experience freezing and thawing cycles. Water seeps into cracks and pores in rocks. When the water freezes, it expands, putting pressure on the surrounding rock. Repeated freeze-thaw cycles cause the cracks to widen, eventually breaking the rock apart.

2. Abrasion: This involves the grinding and scraping of rock surfaces against each other. It can happen in a variety of ways:

* Wind Abrasion: Wind carries sand particles, which act like sandpaper, eroding rock surfaces. This is particularly common in deserts.

* Water Abrasion: Rivers and streams carry sediment, which can scour and abrade the rock beds and riverbanks.

* Glacial Abrasion: Glaciers are powerful agents of abrasion. They carry a huge amount of rock debris, which they use to grind and scrape the underlying bedrock.

3. Exfoliation: This process involves the peeling away of layers of rock, often in large sheets. It occurs primarily in areas with large temperature swings. The outer layers of the rock expand and contract more than the inner layers due to the heat. This creates stresses that can cause the outer layers to peel off. This is common in areas where large igneous intrusions have cooled and contracted.

These are just a few examples of mechanical weathering. Other processes include root wedging (tree roots growing into cracks and breaking the rock), salt wedging (similar to frost wedging, but with salt crystals), and animal activity (burrowing animals can break up rock).