Friction is a necessity and also acts as an evil. Explain.

Friction is both a necessity and an evil because it has useful effects as well as undesirable consequences. There are a lot of examples to justify the statement.

Friction as a Necessity (Useful Effects) :

1. Helps in walking – Without friction between our feet and the ground, we would slip and fall.
2. Enables writing – Friction between pen/pencil and paper allows us to write.
3. Stops vehicles – Brakes work due to friction between brake pads and wheels.
4. Objects can be held – We can hold and grip things because of friction between our fingers and the object.

Friction as an Evil (Harmful Effects) :

1. Wears out machines – Continuous rubbing causes wear and tear in machine parts.
2. Reduces efficiency – Friction converts useful mechanical energy into heat, lowering efficiency.
3. Causes overheating – Moving parts in engines and machines heat up due to friction.
4. Makes movement harder – Extra force is needed to overcome friction while moving heavy objects.

So, from above examples it is visible that Friction is essential for many daily activities, but it also causes damage and energy loss, which is why it is considered both a necessity and an evil