Weathering and Soils: Mechanical Weathering

The video explains mechanical weathering, a process where rocks break into smaller pieces without chemical change. It highlights agents like gravity, plant roots, and temperature fluctuations. Frost action, involving freezing and thawing, is also discussed. The video concludes with a transition to chemical weathering.

What is the primary characteristic of mechanical weathering?

• Rocks break into smaller pieces without chemical change.

• Rocks dissolve in water.

• Rocks change their chemical composition.

• Rocks melt and reform.

How do plant roots contribute to mechanical weathering?

• By wedging apart rocks with their roots.

• By dissolving rocks with acids.

• By absorbing water from rocks.

• By covering rocks with soil.

What effect does temperature fluctuation have on rocks?

• It causes rocks to change color.

• It causes rocks to become magnetic.

• It causes rocks to expand and contract, leading to breakage.

• It makes rocks softer.

What happens to water when it freezes in rock cracks?

• It contracts and leaves the rock intact.

• It turns into a gas and escapes.

• It evaporates and disappears.

• It expands and can force rocks apart.

What is the process called when water freezes and thaws in rocks?

• Erosion

• Sedimentation

• Frost action

• Chemical weathering