Question

What is limiting friction?

Answer 1

Limiting friction is the amount of friction experienced when a stationary object is about to move. To put it another way, it's the least amount of force required to move a stationary item. It is the maximum amount of friction between two materials.

Complete answer:
The friction that is formed between two static surfaces that come into contact with each other is known as limiting friction. It's the sum of the normal force and the limiting friction coefficient. The mathematical representation is as follows:
$F = \mu N$
Where, the limiting friction is denoted by the letter $F$, $\mu$ is the limiting friction coefficient and $N$ stands for normal force.

The laws of limiting friction are as follows:
-The direction of motion and the direction of limiting frictional force are always in opposition.
-The limiting friction acts tangentially to the two surfaces in contact at all times.
-The normal force between the two surfaces and the size of the limiting friction are directly related.
-The material, the type of the surfaces in contact, and the smoothness all influence the limiting friction.
-The limiting friction is independent of the surfaces' shape and area.

Note: Friction value limitation is not self-adjusting. For a pair of materials, it is a fixed value. Depending on the nature of the sliding materials, this may differ. The value of static friction, on the other hand, is self-adjusting. The limiting force of friction is defined as the maximum value of static friction.