Frictional force causes a lot of losses in general upkeep and wear and tear of machinery. Hence it is considered as a evil.
But almost all crucial tasks cannot be carried out without the presence of friction. Basic activities like walking and writing on a surface are possible due to friction. Hence it is considered as a necessary evil .

Introduction:
Friction, often referred to as a necessary evil, is a force that opposes the relative motion between two surfaces in contact. While it may seem like an unwanted force, friction plays a crucial role in various aspects of our daily lives. By providing stability, enabling locomotion, and preventing damage, friction proves to be an essential element in numerous scenarios.

Example - Walking on a Slippery Surface:
Imagine walking on a slippery surface, such as ice or a wet floor. In this situation, friction becomes a necessary evil that ensures our safety and prevents us from slipping and falling. Let's dive deeper into the different aspects of friction in this scenario.

1. Stability:
Friction provides stability when walking on a slippery surface. As we take a step, the friction between our shoes and the ground prevents our feet from sliding outwards. This allows us to maintain balance and stay upright. Without friction, walking on such surfaces would be extremely challenging, as our feet would continuously slide in different directions.

2. Locomotion:
Friction also enables locomotion on slippery surfaces. The friction between our shoes and the ground allows us to push off and propel ourselves forward while walking. Without friction, our shoes would fail to grip the ground, making it nearly impossible to move forward. Thus, friction allows us to move efficiently even on slippery surfaces.

3. Preventing Damage:
Friction acts as a protective mechanism by preventing damage in the case of a fall. When we slip on a slippery surface, the friction between our body and the ground comes into play. This frictional force opposes the relative motion and reduces the impact of the fall. It helps in slowing down our body's movement, minimizing the chances of severe injuries.

Conclusion:
While friction is often seen as an unwanted force due to its ability to impede motion and cause wear and tear, it is undeniably a necessary evil. In the example of walking on a slippery surface, friction ensures stability, enables locomotion, and prevents damage. By understanding the significance of friction in various scenarios, we can appreciate its role and acknowledge the fact that it is an essential force in our daily lives.