Friction – Factors Affecting Friction

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Factors Affecting Friction

Nature of Surface

It depends on the nature of the surface on which the object moves and the nature of the surface of the object. In other words, it depends on the smoothness or the roughness of the two surfaces which are in contact with each

Friction is caused due to the irregularities present on the two surfaces in contact. These irregularities on the surfaces lock into one another.

So whenever we have to move an object, we need to overcome the irregularities. And because rougher surfaces have more irregularities they offer more friction than smooth surfaces.

Lets us consider three cases:-

Case 1: an object with a smooth surface is moving on a surface that is very smooth.

Case 2: the object has a smooth surface and the surface on which it moves is rough or the object has rough surface and the surface on which it moves is rough.

Case 3: the surface of the object as well as the surface on which it moves is rough.

You will find that the force of friction will be lowest in the first case and it will be highest in the third case.

Force with Which the Two Surfaces are Pressed Together

It means if the two surfaces are pressed harder then friction between the two is more. It is because on pressing harder the interlocking between the irregularities of the surfaces

Consider there two bricks kept on a table, one weighing 2 kgs and the other weighing 5 kgs. On applying equal force on them towards the right you will find that the lighter one will travel a greater distance.

It is because the heavier brick presses the surface harder or with more force as compared to the lighter one. Thus more friction is offered and the heavier brick travels a lesser distance.

Summary