Question

Why does frictional force get increased when two surfaces in contact are polished beyond a certain limit?

Answer 1

Hint:Friction can be minimized by eliminating surface irregularities. Polishing aids in friction reduction. By polishing a surface excessively we break the bonds between the molecules of the substance which leads to increasing the irregularities even more.

Complete step-by-step solution:
let us know what friction is:
The resistance to motion of one object moving relative to another is known as friction. It isn't like gravity or electromagnetic in that it isn't a fundamental force. Instead, experts believe it's due to the electromagnetic attraction of charged particles in two adjacent surfaces.
Now lets see why this friction increases when two surfaces in contact are polished beyond a certain limit:
When two surfaces come into contact and are polished past a certain point and made exceedingly smooth, they become intimately connected. Now, the force of adhesion comes into play. The motion of one surface over another is retarded as a result of this force, resulting in an increase in friction.

ADDITIONAL INFORMATION:
There are several exceptions to every basic rule about friction. For example, while two rough surfaces (such as sandpaper) rubbing against one another can cause more friction, very smoothly polished materials (such as glass plates) that have been thoroughly cleansed of all surface particles can actually attach very strongly to each other.

Note:The friction force acts only when there are irregularities on a surface and the friction can be increased only when a frictional force exceeds a certain limit if the rubbing of the surfaces is at the same pace, there won't be any increase in the friction.