Friction and Momentum Quiz

What primarily determines the direction of the friction force between two surfaces?

• The direction of motion
• The direction of the normal force
• The direction of gravity
• The direction of the applied force

Which statement about the coefficient of friction (μ) is correct?

• Always greater than 1
• Always less than 1
• A dimensionless number between 0 and 1
• Measured in units of force

How does static friction compare to kinetic friction?

• Static friction coefficient is usually larger
• Static friction coefficient is usually smaller
• They are always equal
• Static friction only occurs for smooth surfaces

What does the formula f = μN relate to?

• Force and acceleration
• Friction force and normal force
• Friction force and applied force
• Normal force and weight

How is momentum defined in physics?

• Force × time
• Mass × acceleration
• Mass × velocity
• 1⁄2 × mass × velocity²

Which of the following quantities shares the same direction as momentum?

• Force
• Acceleration
• Velocity
• Position

What does the change in momentum of an object equal?

• Mass × change in velocity
• Force × time (impulse)
• Both a and b
• Neither a nor b

If an object is moving at a constant velocity, what can be said about the net force acting on it?

• It is zero
• It is equal to the weight of the object
• It is equal to the friction force
• It is equal to the applied force

Which of the following factors does NOT affect the frictional force between two surfaces?

• Surface roughness
• Normal force
• Velocity of the object
• Material properties

What happens to the friction force when the normal force increases, assuming the coefficient of friction remains constant?

• It decreases
• It increases
• It remains the same
• It becomes zero