Although friction is of great importance in our daily life, yet in many situations, it acts evil.
- Friction produces heat that causes objects to wear out.
- Friction makes work tedious. Because of the resistance workers need to exert more effort and energy both to accomplish their work and to overcome resistance.
- Friction also causes sparks, overheating and machine breakdown.
- Friction reduces speed. Even airplanes cannot fly as fast as they are able because of air friction.
- Friction can also make speeding objects to tumble down and cause accidents.
- Racing cars and other vehicles consume more energy to run fast and overcome the resistance of the roads.