All Flashcards

Define kinetic friction.

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

Define static friction.

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

Define the coefficient of kinetic friction ( $mu_k$ ).

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

Define the coefficient of static friction ( $mu_s$ ).

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

Define normal force ( $F_n$ ).

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

How do you calculate kinetic friction ( $F_k$ )?

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

How do you calculate the maximum static friction force ( $F_{f,s,max}$ )?

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

What is the process to determine if an object will move when a force is applied, considering static friction?

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.

What are the steps to solve a problem involving kinetic friction on a horizontal surface?

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.

What are the steps to solve a problem involving static friction on a horizontal surface?

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.

In a diagram of kinetic friction, label the forces acting on a block sliding to the right.

1: Applied Force (right), 2: Kinetic Friction (left), 3: Normal Force (up), 4: Weight (down)

In a diagram of static friction, label the forces acting on a stationary block with an applied force to the right.

1: Applied Force (right), 2: Static Friction (left), 3: Normal Force (up), 4: Weight (down)

Label the forces acting on a block sliding down an inclined plane with kinetic friction.

1: Weight (down), 2: Normal Force (perpendicular to plane), 3: Kinetic Friction (up the plane), 4: Component of Weight parallel to the plane (down the plane)

Label the forces acting on a block at rest on an inclined plane due to static friction.

1: Weight (down), 2: Normal Force (perpendicular to plane), 3: Static Friction (up the plane), 4: Component of Weight parallel to the plane (down the plane)

Label the forces on a free body diagram of an object being pushed horizontally with friction.

1: Applied Force (horizontal), 2: Friction Force (opposite applied force), 3: Normal Force (vertical), 4: Gravitational Force (vertical)