An avalanche takes place when ice and snow move down a slope with great speed. What effect does friction have on its rate of movement?
A.
Friction causes the avalanche to move rapidly.
B.
Friction creates a curved surface that decreases the speed.
C.
The speed of the avalanche decreases with increased friction.
D.
The speed of the avalanche increases with increased friction.
E.
Friction does not have any effect on the avalanche.