Friction is often called a necessary evil as it has both positive and negative effects. Some of the positive effects of friction are:

• It provides the necessary force for walking. It is very difficult to walk on a slippery surface.


• It helps us write on blackboard with a chalk. If friction was absent, chalk wouldn't remain stuck on the blackboard.


• It is because of friction that a nail remains fixed to the wall.

There are many other positive effects of friction as well. However, friction causing wear and tear of shoes is not desirable.