Question

why is friction said to be a necessary evil?give long answer

Answer 1

Is is a general misconception that friction always opposes motion between two bodies in contact ,but actually it opposes relative motion between two bodies in contact .In many cases friction is found as the cause of motion .without friction it is impossible to imagine this world. Friction is evil in mechanical machines causing wear and tear of parts.Friction causes wear and tear of tyre but in turn is impossible to rotate tyre…and many more.

Answer 2

Friction is often regarded as necessary evil because in some cases it is necessary but in some not,like-while walking we need friction