If material is to move down slope, it must overcome the force of ...

[Jramos095]

If material is to move down slope, it must overcome the force of
 
  A) inertial resistance of the material only.
  B) the cohesion of particles to each other only.
  C) friction only.
  D) both friction and inertial resistance.
  E) friction, cohesion of particles, and inertial resistance.

Question 2

The frictional force effect on winds
 
  A) is negligible at altitudes above 500 m (1,600 ft).
  B) increases with increasing altitude.
  C) is constant, regardless of time of day or year.
  D) is greatest in the upper troposphere.
  E) is lessened in areas with rougher surfaces.

[Harbringer]

Answer to Question 1

E

Answer to Question 2

A