The coefficient of kinetic friction:
A)is in the direction of the frictional force
B)is in the direction of the normal force
C)is the ratio of force to area
D)can have units of newtons
E)none of the above

Question

Quizplus · Accepted Answer

The coefficient of kinetic friction is a dimensionless quantity that represents the ratio of the force of kinetic friction between two bodies and the normal force pressing them together. It does not have a direction (making A and B incorrect), it is not a ratio of force to area (making C incorrect), and it does not have units of newtons (making D incorrect) because it is a ratio of forces, which cancels out the units.

The Coefficient of Kinetic Friction