09-24-25 Unit 4 Friction

Normal Force

The perpendicular component of force resulting from the compression of surface molecules.

Friction

A sideways force that resists motion when an object is pulled across a surface.

Static Friction

Friction that is present when forces try to cause sliding but the objects don't slide.

Coefficient of Static Friction (μs)

The ratio that defines the maximum static friction force exerted between two surfaces.

F_s,max

The maximum static friction force, calculated as μs multiplied by the normal force.

Kinetic Friction

Friction that is present when objects are sliding against each other.

Coefficient of Kinetic Friction (μk)

The ratio that defines the kinetic friction force between moving surfaces.

Net Force

The total force acting on an object, resulting from the combination of all the forces.

Applied Force

The force exerted on an object to cause movement.

Gravity Force (F_g)

The gravitational force acting on an object, calculated as the mass of the object multiplied by the acceleration due to gravity.

Friction Force (f_s)

The force exerted by friction, counteracting the applied force when an object does not move.

Magnitudes of Forces

The size of forces acting in various directions, important in calculating net force.