Question

What causes friction between two seemingly smooth surfaces?

A. There is an invisible force sticking the surfaces together.
B. The surfaces really aren't smooth. It's just an illusion.
C. Surfaces that are too smooth tend to stick together.
D. Tiny collisions on the surfaces, called microwelds, cause friction.

Answer 1

Friction between smooth surfaces is caused by microwelds, which are tiny collisions on the surfaces that create resistance and prevent smooth sliding.

Step-by-step explanation:

Friction between two seemingly smooth surfaces is caused by tiny collisions on the surfaces, known as microwelds. When two surfaces come into contact, the asperities (tiny ridges and bumps) on the surfaces interlock, creating resistance as the surfaces try to slide past each other. This resistance is what we perceive as friction.

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