Frictional Force

Friction is a force that resists the relative motion or tendency of such motion between two surfaces in contact. It always acts in the direction opposite to the motion or tendency of motion.

Types of Friction

Static Friction: This type of friction acts between surfaces at rest with respect to each other.
Kinetic Friction: This type of friction acts between surfaces in relative motion.
Rolling Friction: This type of friction occurs when an object rolls over a surface.

Factors Affecting Friction

Surface Roughness: Rough surfaces have higher friction than smooth surfaces.
Normal Force: Friction is directly proportional to the normal force between the surfaces.
Type of Material: Different materials in contact exhibit different levels of friction.
Temperature: Friction is affected by temperature, with some materials having lower friction at higher temperatures.

Calculating Frictional Force

The force of friction can be calculated using the formula:

F_f = μN

Where:
F_f = force of friction
μ = coefficient of friction
N = normal force

Applications of Frictional Force

Frictional force has various practical applications, such as in:

Brakes in vehicles
Walking or running
Using tools such as screwdrivers or wrenches
Preventing slipping of objects

Summary

Friction is a fundamental force that plays a crucial role in our daily lives. Understanding the factors affecting friction and how to calculate frictional force is important in various fields of physics and engineering.

◂Physics Worksheets and Study Guides High School. Forces - Set I

The resources above cover the following skills:

PHYSICS

Motion and Stability: Forces and Interactions

Identify and analyze forces responsible for changes in rotational motion and develop an understanding of the effect of rotational inertia on the motion of a rotating object (e.g., merry-go-round, spinning toy, spinning figure skater, stellar collapse [supernova], rapidly spinning pulsar).