Question

which is an example of erosion? (1 point) water in a river smoothing down rocks. roots of a tree breaking apart a rock sand being pulled away from a beach by waves. what does physical weathering involve? (1 point) all of the above wind temperature water

Explanation:

First Question (Example of Erosion)

Erosion is the process of transporting sediment (like sand, soil, rock fragments) by natural agents (water, wind, ice, gravity). Let's analyze each option:

• "water in a river smoothing down rocks" is abrasion (a type of weathering, specifically physical weathering where rocks are worn down by water movement with sediment).
• "Roots of a tree breaking apart a rock" is biological weathering (tree roots exert force to break rock, not transporting it).
• "Sand being pulled away from a beach by waves" is erosion because waves are transporting the sand (sediment) from the beach.

Physical weathering is the breakdown of rocks into smaller pieces without changing their chemical composition. Agents of physical weathering include:

• Wind: can carry sediment that abrades rocks or cause rocks to collide.
• Temperature: causes thermal expansion and contraction of rocks, leading to cracking.
• Water: can freeze (ice wedging, where water freezes in cracks, expands, and breaks rock) or move sediment to abrade rocks.

Since wind, temperature, and water are all agents of physical weathering, "All of the Above" is correct.

Answer:

Sand being pulled away from a beach by waves. (the option with "Sand being pulled away from a beach by waves.")

Second Question (What does physical weathering involve?)