Question

What is friction force?
explain for 3 marks​

Answer 1

Answer:

Friction force is the force that opposes relative motion between two surfaces that are in contact.

Example

As an object falls, air resistance pushes up on the object. When you ride a bicycle, the contact between the wheel and the road is an example of rolling friction. When an object rolls over a surface, the force needed to overcome rolling friction is much less than that needed to overcome sliding friction.

Answer 2

Friction Force

==> The force which comes into action whenever there is relative motion or tendency of relative motion.

==> When one body move or tend to move on another body than the force that opposes motion or tendency of motion is known as friction force.

==> Friction force always opposes relative motion.

==> The friction force acting between two forces depends only upon actual contact area it does not depend upon appearent area of contact.

Example ;

When two highly polished surface are pressed hard against each other then a process similar to welding occur which is known as cold welding.