Unit 37 Review Questions

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. Why does slope failure occur when a slope is oversteepened?

Gravitational force is no longer opposed by any other forces. correct incorrect

Gravitational force and frictional force become equal. correct incorrect

Gravitational force is expressed entirely along the slope's angle of repose. correct incorrect

Gravitational force is stronger than the combined forces of friction and cohesion. correct incorrect

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. What is the main way that tree roots can help stabilize a slope?

Tree roots decrease the frictional force of the slope. correct incorrect

Tree roots lower the gravitational force on the slope. correct incorrect

Tree roots decrease the angle of the slope. correct incorrect

Tree roots increase the cohesion of the slope. correct incorrect

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. Movement downslope of more or less intact blocks of material along a curved surface is termed:

creep correct incorrect

slump correct incorrect

flow correct incorrect

fall correct incorrect

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. Debris flows:

require saturated slopes correct incorrect

usually move very slowly correct incorrect

often move down an existing stream channel correct incorrect

rarely threaten human lives correct incorrect

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. Rainfall causes many mass movements because it:

decreases the force of gravity on the slope correct incorrect

increases the amount of air in soil pores correct incorrect

changes the temperature of the slope correct incorrect

reduces friction in the slope correct incorrect

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. Which type of mass movement results in the formation of talus?

Debris flow correct incorrect

Earth flow correct incorrect

Fall correct incorrect

Slump correct incorrect

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. Solifluction is most common:

at high latitudes correct incorrect

in desert regions correct incorrect

in humid midlatitude climates correct incorrect

in the tropics and subtropics correct incorrect