B.2.1.3 Friction (HL)

What is the definition of friction?

A force that acts parallel to the interface of two surfaces that are in contact and opposes their relative motion.

What type of surfaces have high friction?

Dry and rough surfaces.

What type of surfaces have low friction?

Smooth and wet surfaces.

What are the two types of friction?

Static friction and dynamic friction.

What is static friction?

The force that resists the movement of an object which is in contact with another surface.

What is dynamic friction?

The force of two objects that are sliding against each other.

What is the coefficient of friction?

A numerical value that is used to predict/calculate the force of friction in various situations.

What factors affect the magnitude of the coefficient of friction?

The materials in contact and the interaction between the molecules of the interacting surfaces.

What is the range of the coefficient of friction?

Between 0 and 1 (occasionally higher).

What is the relationship between the coefficient of static friction and dynamic friction?

Coefficient of static friction (COSF) is usually higher than the coefficient of dynamic friction (CODF).

How can friction be maximized in sports?

By changing the playing surface, adjusting footwear, using specific equipment, and manipulating temperature.

How can friction be minimized?

By changing the playing surface to wet or waxed, using specialized footwear like ice skates, or adding lubricants.