Kinetic Friction Formula

What is Kinetic Friction?

Kinetic friction, commonly known as sliding friction occurs when two surfaces are rubbed past one another. Whereas static friction that occurs when the objects are stationary does not apply in the case of kinetic friction, in which the object is already moving.

Formula 

The Resisting force experienced as kinetic friction in the two moving aircrafts as they contact with each other. The kinetic friction is represented by 

Where,

• Fk is Force of kinetic friction

• the coefficient of kinetic friction is μk

• the normal force is Fn

Kinetic friction formula is helpful in questions to find the friction between the bodies that are in motion. The unit of frictional force is newton (N).

Solved Problem

Problem 1: A boy playing volleyball is throwing a force of 200N and given that coefficient of friction 0.8. Now find its kinetic friction? 

Answer:

 Given

μk = 0.8

Fn = 200 N

Formulation of the Kinetic friction 

Fk = μk Fn

Fk = 0.8 x 200

Fk = 160 N