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
`0 lt= f_s lt= mu_s N`
where ,`mu_s` - coefficient of static friction
N - Normal force
Kinetic friction: The frictional force exerted by the surface when an object slides as kinetic friction. Also called as sliding friction or dynamic friction,
`f_k = mu_ k N`
where `mu_k` - the coefficient of kinetic friction
N - Normal force exerted by the surface on the object
Methods to reduce friction: Friction can be reduced
(i) By using lubricants (ii) By using Ball bearings (iii) By polishing (iv) By streamlining