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