Question

What is meant by limiting friction?

Answer 1

Limiting friction is the friction at which a body just begins to move but is not quite moving yet.
Limiting friction is slightly greater than the static friction.
example:
Think that you are pushing a heavy toy and it refuses to move from its place.So you put on more and more amount of force to move it and just at the verge the toy starts to move...This force you applied is the amount of limiting friction . Any force greater than this will cause acceleration in the body and it will move in the direction of applied force.

Laws of Limiting Friction
1. Limiting friction acts tangential to the two surfaces in contact.
2. The direction of limiting friction is always opposite to the direction of motion.
3. The magnitude of limitinf friction is directly proportional to normal reaction between two surfaces.
4. The liiting friction depends upon the material, the nature of surface in contact and their smoothness.
5. For any two given surface, the magnitude of limiting friction is independent of the shape or the
area of the surfaces in contact so long as the normal reaction remains the same