Some Other Laws

Other than these laws, there are some more laws which help us govern the concept of friction. These are:

• Coulomb’s Law of Friction
• Law of Static Friction
• Law of Kinetic Friction

Coulomb’s Law of Friction

Coulomb’s Law of Friction, formulated by Charles-Augustin de Coulomb, describes the relationship between the frictional force and the normal force acting between two surfaces in contact. It is the extension of Amontons’ First Law as it it introduces the constant of proportionality i.e., μ. Mathematically, coulomb’s law of friction is given as follows:

F_f = μ . N

Where,

• F_f is the force of friction,
• μ is the coefficient of friction, and
• N is the normal force.

Law of Static Friction

The maximum static friction force ([Tex]F_{f_s}[/Tex]) that can exist between two stationary surfaces is directly proportional to the normal force (F_N​) acting perpendicular to the surfaces. The coefficient of static friction (μ_s​) represents the proportionality constant. Mathematically, [Tex]F_{f_s}[/Tex] ≤ μ_s​⋅F_N.

The static friction force opposes the impending motion or attempted motion between the surfaces. It acts tangentially to the surfaces in contact.

Law of Kinetic Friction

Kinetic friction force ([Tex]F_{f_k}[/Tex]​​) is directly proportional to the normal force (F_N​), which is the force perpendicular to the surfaces in contact. The coefficient of kinetic friction (μ_k​) represents the proportionality constant. Thus, [Tex]F_{f_k}[/Tex] =μ_k​⋅F_N.

The kinetic friction laws describe that the friction force acting against the motion of an object is dependent upon factors such as the roughness of the surface and the magnitude of the normal force.

Also, Read

Friction is a fundamental force that affects our everyday lives. When we slide a book across a table or walk on a slippery surface, friction comes into play. There are various laws which govern the phenomenon of friction such as Amonton’s and Columnb’s Laws. In this article, we will discuss all the laws which help us understand the concept of Friction.