All Flashcards
What is kinetic friction?
A force that opposes the motion of surfaces sliding against each other.
What is static friction?
A force that prevents surfaces from slipping when they are at rest relative to each other.
Define the coefficient of kinetic friction ().
An empirical value that depends on the materials of the contacting surfaces, used to calculate kinetic friction.
Define the coefficient of static friction ().
An empirical value that depends on the materials of the contacting surfaces, used to calculate the maximum static friction force.
Define normal force (N).
The force acting perpendicular to the surface of contact.
What is the effect of increasing the normal force on kinetic friction?
Increasing the normal force increases the magnitude of the kinetic friction force ().
What is the effect of the applied force exceeding the maximum static friction?
The object begins to move, and kinetic friction replaces static friction.
What happens if the coefficient of static friction increases?
It becomes harder to start moving the object because the maximum static friction force increases.
What is the effect of a non-zero net force when kinetic friction is present?
The object will accelerate according to Newton's Second Law ().
What happens when the applied force is less than the maximum static friction force?
The object remains at rest, and the static friction force equals the applied force.
What is the effect of increasing the normal force on kinetic friction?
Increasing the normal force increases the magnitude of the kinetic friction force.
What happens when the applied force exceeds the maximum static friction?
The object begins to move, and kinetic friction takes over.
What is the effect of friction on the work-energy theorem?
Friction does negative work, converting kinetic energy into thermal energy, thus reducing the total mechanical energy.
What happens when a car tire rolls without slipping?
Static friction between the tire and the road provides the centripetal force needed for circular motion.
What is the effect of a higher coefficient of static friction between two surfaces?
It requires a greater force to initiate movement between the surfaces.