Question

how friction is caused?????

Answer 1

The causes of this resistive force are molecular adhesion, surface roughness, and deformations. Adhesion is the molecular force resulting when two materials are brought into close contact with each other.

Answer 2

hey mate your answer is...

cause of friction verey very small goves of bumbs ( roughness surface) on which can't seen naked eyes. These goves can observed by microscope. micrscope. When two surfaces are rubbed against each other these grooves and bumps collide each other and cause tendency to oppose movement causing friction.