Question

Explain the methods of reducing as well as icreasing friction with proper examples

Answer 1

we can decrease by using lubricants oils rtf
we can increase by increasing irregularities

Answer 2

To increasing the friction ;

1 Roughen the surface: example Treaded tyres of vehicles have grooves to increase friction.
2 Dry the surface: example  sand and gravel is thrown on slippery ground to increase friction.
3 Use brake pads: example we use break pads in the brake system.

To decrease the friction ;

1 Polishing the surface reduce friction.
2 Lubricating the surface: like oil  and water to make the surface slippery.
3 Using wheels and ball bearings to make  the vehicles move easily.
4 Streamlining the shapes like boats to reduce the air drag.