Which of the Following Statements Is NOT True About Friction

Multiple Choice

Which of the following statements is NOT true about friction?

A) µ_k is less than µ_s
B) µ_k is independent of the relative speed of the surfaces in the range of about 1 cm/s to several meters per second.
C) µ_k depends on the relative speed of the surfaces at speeds over several meters per second.
D) The coefficients of friction depend on the nature of the surfaces.
E) The force of static friction depends on the area of contact between the two surfaces.