Explain various types of friction suggest a few methods to reduce friction

Explanation

There are two types of Friction
(i) Static Friction: Static friction is the force which opposes the initiation of motion of an object on the surface. The magnitude of static frictional force `f_s` lies between
`I lt= f_s lt= mu_s N`
where `mu_s` - cefficient of static friction
N - normal force
Kinetic friction: The frictional force exerted by the surface when an object slides is called as kinetic friction. Also called as sliding friction or dynamic friction
`f_s = mu_s N`
where `mu_s ` - the coefficient of kinetic friction
N - normal force exerted by the surface on the ebject
Methods to reduce friction: Friction can be reduced
( i) By using lubricants
(ii) By using Ball bearings
(iii) By polishing
(iv) By streamlining