Kinetic Friction

Kinetic FrictionFriction is easily defined as the force that holds back a sliding object. The kinetic friction is a part of everything and it interfere motion of two or more objects. The force acts in the opposite direction to the way an object wants to slide. If a car has to stop, we apply brakes and that is exactly where friction comes into play. While walking, when one wants to suddenly come to a halt, friction is to thank again. But when we have to stop in the middle of a puddle, things get harder since friction is less there and cannot aid one so much.

There are two main types of friction, static friction and the kinetic friction. Static friction is the one present between two objects that are not moving with respect to each other. In liquids friction is the resistance between moving layers of a fluid better known as viscosity. Now take two moving solid objects, this is known as moving or kinetic friction due to its motion. This friction is particular fraction of the perpendicular force acting between two bodies. A coefficient of friction determines the fraction which in turns determined through experiments. The force is independent of the contact area and doesn’t change no matter how fast the two objects are moving. While in contrast, static friction is what affects stationary objects. The force of friction is a force that resists motion when two objects are in contact. If you look at the surfaces of all objects, there are tiny bumps and ridges. Those microscopic peaks and valleys catch on one another when two objects are moving past each other. There are of course other forces at work like chemical bonding and electrical interactions.

Friction also plays a huge role in everyday occurrences like while rubbing of two objects takes place. The resulting motion converts into heat and thus resulting in the fire in some instances. Friction is also responsible for wear and tear and that’s why we need oil to lubricate machine parts, as it reduces friction.

Stay tuned with Byju’s to understand the different concepts and facets of friction.

Practise This Question

Identify the correct sequence of events that take place when an external force acts on a block (at rest) kept on a rough surface.

A. The block starts moving.
B. Static friction starts acting on the block.
C. Kinetic friction acts on the block.
D. The block continues to be stationary.