The force that opposes the motion of two surfaces sliding against each other.

The force that opposes the start of motion between two surfaces in contact.

A dimensionless quantity representing the 'roughness' between two surfaces in kinetic friction. It relates the kinetic friction force to the normal force.

A dimensionless quantity representing the 'stickiness' between two surfaces in static friction. It relates the maximum static friction force to the normal force.

The force exerted by a surface that is supporting the weight of an object. It acts perpendicular to the surface.

$|F_k| = |mu_k F_n|$, where $mu_k$ is the coefficient of kinetic friction and $F_n$ is the normal force.

$F_{f,s,max} = mu_s F_n$, where $mu_s$ is the coefficient of static friction and $F_n$ is the normal force.

1. Calculate the maximum static friction force ($F_{f,s,max} = mu_s F_n$). 2. Compare the applied force ($F_{applied}$) with the maximum static friction. 3. If $F_{applied} > F_{f,s,max}$, the object will move; otherwise, it remains at rest.

1. Draw a free-body diagram. 2. Determine the normal force ($F_n$). 3. Calculate the kinetic friction force ($F_k = mu_k F_n$). 4. Apply Newton's Second Law to find the net force and acceleration.

1. Draw a free-body diagram. 2. Determine the normal force ($F_n$). 3. Calculate the maximum static friction force ($F_{s,max} = mu_s F_n$). 4. Compare the applied force with the maximum static friction force to determine if the object moves.

Increasing the normal force increases the magnitude of the kinetic friction force ($F_k = mu_k F_n$).

The object begins to move, and kinetic friction replaces static friction.

It becomes harder to start moving the object because the maximum static friction force increases.

The object will accelerate according to Newton's Second Law ($F = ma$).

The object remains at rest, and the static friction force equals the applied force.