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.
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.
Compare and contrast static and kinetic friction.
Static Friction: Acts on stationary objects, prevents motion, adjustable up to a maximum value. | Kinetic Friction: Acts on moving objects, opposes motion, constant value.
What are the key differences between and ?
: Coefficient of static friction, applies to objects at rest, usually greater than . | : Coefficient of kinetic friction, applies to objects in motion, usually less than .
Compare the force of static friction to the applied force before movement occurs.
Static Friction: Equal in magnitude and opposite in direction to the applied force, up to the maximum static friction force. | Applied Force: The external force attempting to initiate movement.
Compare the force of kinetic friction to the applied force when an object is moving at a constant velocity.
Kinetic Friction: Equal in magnitude and opposite in direction to the net applied force. | Applied Force: The external force that, in combination with kinetic friction, results in zero net force and constant velocity.
Compare the effect of surface area on static vs kinetic friction.
Static Friction: Magnitude is independent of the contact area between the surfaces. | Kinetic Friction: Magnitude is independent of the contact area between the surfaces.