When two surfaces are polished, the friction coefficient between them decreases. But the friction coefficient increases and become very large if the surfaces are made highly smooth. Explain.
Answers
Answer ⇒ When the surfaces are highly polished then the Friction coefficient between them as a result Friction decreases this is because, When two surfaces are polished the undulations on the surfaces reduce and it offers less resistance to sliding on each other.
The actual points of contact where molecular bonds are formed is less. So the friction coefficient between them decreases. Hence, Friction also decreases.
When these surfaces are made highly smooth the actual contact points between them increases many folds. At these points molecular bonds are formed. To slide them over each other a large amount of force is needed to break these molecular bonds. So the coefficient of friction becomes very large. As a result the Friction Increases.
Hope it helps.
Answer:
due to cold welding bond are strongly form between surface
Explanation: