1. What happens in physical weathering?

2. What is another name for physical weathering?
3. What forces are involved in physical weathering?

1. Physical weathering refers to the process in which rocks and minerals break down into smaller pieces by various physical forces. These forces can include temperature changes, wind action, water movement, ice formation, plant roots, and even the activities of humans and animals. In physical weathering, the chemical composition of the rock or mineral remains the same, but the physical structure is altered.

2. Another name for physical weathering is mechanical weathering. This term emphasizes the mechanical forces that cause the breakdown of the rocks and minerals. It is important to note that physical weathering is different from chemical weathering, which involves the alteration of the rock's chemical composition through chemical reactions.

3. Physical weathering involves several forces that contribute to the breakdown of rocks and minerals. Some of the common forces include:

- Temperature changes: Repeated heating and cooling of rocks can cause expansion and contraction, leading to cracks and fractures. This process is known as thermal expansion and contraction.

- Wind action: Strong winds can carry abrasive particles like sand and dust, which can impact rocks and cause them to break down over time. This process is often seen in deserts and coastal areas.

- Water movement: The movement of water can cause erosion and wear away rocks over time. Water flowing in streams or waves crashing onto coastlines can exert significant pressure on rocks, leading to their gradual breakdown.

- Ice formation: The expansion of water as it freezes can exert tremendous pressure on surrounding rocks, causing them to fracture. This process, called frost wedging, is particularly common in cold climates or areas with freeze-thaw cycles.

- Plant roots: As plants grow, their roots can exert pressure on rocks, exploiting existing cracks and eventually causing them to split apart. Plant roots also release chemicals that can contribute to rock weathering.

- Human and animal activities: Human activities like construction, mining, and the use of machinery can physically break down rocks. Animals can also contribute to physical weathering through burrowing or digging activities.

All these forces work collectively to break down rocks and minerals into smaller pieces through physical weathering.