Solve for x: x3 5x2 4x 20 0.
Topic: Weathering Takes longer in dry environments; accelerates in wet environments Types of Weathering: 1) Mechanical/Physical: breakup of rock into smaller rocks a. Frost Wedging: involves expansion and contraction of water in rock crack due to freezing and thawing b. Frost heaving: Up thrust of sediment or soil due to the freezing of wet soil beneath c. Salt crystal growth: involves buildup of salts on rock surfaces through evaporation. Salt weakens the rock, making it vulnerable d. Exfoliation: sheets of rock flake away due to seasonal temperature changes or by the expansion of rock due to unloading 2) Chemical: dissolves the rock a. Oxidation: oxygen chemically combines with metallic iron to form iron oxides, losses in elections. (color changes) b. Carbonation: caused by rain water that has absorbed atmospheric carbon dioxide c. Acid rain: human cause. Precipitation of strong mineral acids, primarily sulfur dioxide and nitrogen oxides, originating in factories. 3) Differential: two different rock types weather at different rates Mass wasting: movement of rock, sediment and soil downslope due to force of gravity Happens when downward force of gravity overcomes the resisting force of the slope’s material shearing strength Colluvium – unconsolidated sediment that accumulates at the base of slope Types of mass wasting: 1) Rock fall 2) Soil creep 3) Landslides 4) Slump 5) Earth flow 6) Mudflow 7) Avalanches