Question

If two pieces of same metal having Ultra smooth surfaces are kept in contact comment on the friction between two surfaces when we try to move one on the other justify your answer with proper reasons.

How do F1 cars manage to develop friction even though they don't have treading

Answer 1

The friction will be very high.
Reason is as follows,
If the two surfaces of the same material are very smooth, the molecules and atoms of one surface get closer to the molecules and atoms of the other surface. As they get closer the molecular cohesive forces begin to take effect and the two surfaces will actually stick to each other. If the surfaces are rough there are far fewer molecules that are close but the rough surface against another rough surface causes friction as in two bricks rubbing against eachother. You can try this with two polished surfaces of metal or glass.