El desgaste y la erosión: desgaste mecánico

The video tutorial explains mechanical wear, a process where rocks and materials change physically without chemical alteration. It covers various forces causing mechanical wear, such as gravity, abrasion, temperature changes, and the freezing and thawing of water. Examples include landslides, river abrasion, and the formation of fairy chimneys. The role of plant roots in expanding rock cracks is also discussed.

What is the primary effect of mechanical wear on rocks?

• It makes them heavier.

• It breaks them into smaller pieces.

• It alters their color.

• It changes their chemical composition.

How does abrasion affect rocks?

• It changes their color.

• It smoothens and rounds them.

• It increases their size.

• It makes them more jagged.

What happens to rocks when they are exposed to fluctuating temperatures?

• They become chemically altered.

• They change color.

• They expand and contract, leading to breakage.

• They melt.

What is the result of water freezing in rock cracks?

• The cracks become narrower.

• The water evaporates.

• The cracks widen as the water expands.

• The rocks become softer.

How do plant roots contribute to mechanical wear?

• They chemically alter the rocks.

• They make rocks heavier.

• They prevent rocks from breaking.

• They penetrate and widen cracks over time.