Friction is wasteful at times so why we need to increase it in cases ?
Answers
There is a great impact if the friction turns out to be waste in many extreme cases
The value of friction depends on the normal force and the coefficient of friction. This coefficient of friction depend on the type of material.
We can increase the value of friction by making the surface very rough and this would help in extreme cases .
For example 1)a vehicle moving on a road with high speed needs more friction but if the friction fails there then there would a fatal accident and thus would be very dangerous and for that purpose the road is made with tar or cement which increases the value of friction capacity
2)When we move over an inclined plane we need more friction or else the tendency to slip will increase and thus the walker may fall down and get injuries
And there are many more examples where friction plays an important role
hence we need to increase the value of friction to avoid any serious damages
Hope this helped u :-)