Question

multiple choice question
which statement best describes the relationship between the coefficient of kinetic friction and the coefficient of static friction for most surfaces?
o the coefficient of static friction is larger than the coefficient of kinetic friction for some combinations of materials, and smaller for others.
o the coefficient of kinetic friction is a larger value than the coefficient of static friction.
o the coefficient of static friction is the same value as the coefficient of kinetic friction.
o the coefficient of static friction is a larger value than the coefficient of kinetic friction.

Explanation:

Static friction acts when an object is at rest and needs to be overcome to start motion. Kinetic friction acts when the object is already in motion. Once an object is moving, less force is needed to keep it moving compared to the force needed to start its motion. This implies that the coefficient of static friction (\(\mu_s\)) is generally larger than the coefficient of kinetic friction (\(\mu_k\)) for most surface - material combinations. For example, when pushing a heavy box, it is harder to start moving it (static friction) than to keep it moving (kinetic friction).

Answer:

The coefficient of static friction is a larger value than the coefficient of kinetic friction.