- Books Name
- Class-8 Science Book
- PathSet Publications
- CBSE Class 8
FRICTION: A NECESSARY EVIL
Friction is a necessary evil because it is both harmful and beneficial effects in everyday life.
Friction is necessary. Without friction -
▪ No moving object can stop.
▪ No building can be constructed.
▪ We will not be able to write with pen or paper.
▪ We will not be able to walk.
Friction is evil because:
- Friction wears out the materials whether they are screws, ball bearings, or sole of shoes.
- Friction produces heat causing wastage of energy in machines.
- Friction causes moving objects to stop or slow down.
- Soles of shoes have grooves on them. Grooved soles provide more friction to the ground which gives better grip when we walk.
- We can walk easily because the ground offers friction. So, friction is necessary even in a simple task like walking.
- It is a difficult task to move on a wet muddy track or wet marble floor. This is because these surfaces offer very small friction to the surface of the feet of a person.