5 Facts On Rolling Friction And Sliding Friction

Friction is regarded to be one of the forces which opposes the motion of two objects when in contact. Let us study in further several facts about friction and its type.

Rolling friction occurs when an object is allowed to roll over a surface of contact and sliding friction occurs when any two objects are allowed to rub against each other. Rolling friction appears when the surface of contact changes the shape due to application of an external force.

In this article we will be discussing, is sliding friction lesser than rolling friction, how does sliding friction work, rolling friction and sliding friction difference, relation between rolling friction and sliding friction and force of rolling friction and sliding friction.

Is sliding friction lesser than rolling friction?

Resistance offered by the surface is called as friction. Let us see if sliding friction less than rolling friction.

Sliding friction is not lesser than rolling friction because when the microscopic surfaces of the two objects in motion cojoins, which is absent in rolling friction. Sliding friction is the friction majorly noticed in ball bearings. The interaction between the surface and the object is strong in sliding friction.

Sliding friction is the kind of friction in which the force is exerted on the object at motion, meaning, when the object is sliding on the surface of contact. In comparison to the sliding friction, static friction is stronger since the force exerted on the object at rest.

How does sliding friction work?

Sliding friction is applied on two objects under motion relative to each other. Let us see how sliding friction works.

Sliding friction is created when on objects slides over the other. Sliding friction is also regarded to be kinetic force which keeps the two bodies in contact under constant motion. Sliding friction basically depends on two factors, namely, the material of the object and weight of the object.

In sliding friction, the intermolecular force of attraction takes place due to which sliding friction is often less than the static friction. Several facts that affect sliding friction are, object size, speed of both the objects under motion, surface of contact and the pressure applied on objects.

Rolling friction and sliding friction difference

Friction types primarily depends on the type of motion they are under. Let us examine the difference between rolling and sliding friction.

Rolling Friction Sliding Friction
 Rolling friction requires one object and one surface of contact. Sliding friction requires two objects in contact under motion and one surface.
Rolling friction takes place when an object is allowed to rolls on the surface of contact. Sliding friction occurs when two objects rub against each other or slides along the surface.
Rolling friction depends on the geometry of the object and surface deformation. Sliding friction depends on the type of material of the object and the cojoining of microscopic surface of the objects.
The formula for rolling friction is given by
fr = μr N
 The formula for sliding friction is given by
fk = μk N
Difference between rolling and sliding friction

Relation between rolling friction and sliding friction

Friction is the resistance applied on the objects under motion. Let us see the relation between rolling and sliding friction.

The relation between the rolling friction and the sliding friction is coefficient of friction. The coefficient of friction μ is regarded to be the ration between the frictional force and normal force, coefficient of rolling and sliding friction is so the ration between their respective frictional forces to the normal force.

The coefficient of friction primarily depends on the Amonton-Coulomb Law. The law enforces that the frictional force and normal force are directly proportional to each other. Similarly, the rolling and sliding frictional forces are directly proportional to the normal force (applied load) respectively.

750px Friction.svg
Image Credits: Frictional Force by Keta, Pieter Kuiper (CC BY 2.5)

Relation between rolling friction and sliding friction

Friction force opposes the motion between two objects. Let us learn force of rolling friction and sliding friction.

 Force of Rolling Friction Force of Sliding Friction
The force of friction that opposes the rolling motion of the body in contact with surface is called rolling frictional force.  The force that opposes the sliding motion of the objects in contact with surface is called as the sliding frictional force.
In rolling friction, the force is applied on all parts of the object when in motion. Example, moving of wheels on roads.  In sliding friction, the force is applied on one part of one side of the object and force restricted on other side of the object. Example, pushing a box on the floor.
 In rolling friction, rolling frictional force is directly proportional to the normal force.  In sliding friction, normal force and sliding force is directly proportional to each other.
In this case, only the particular part of the object is in contact with the surface considered. In this case, vast area of the object comes in contact with the surface and not in points.
Relation between rolling friction and sliding friction

Conclusion

In this article we come to a conclusion that rolling friction and sliding friction are the types of friction where both are the resistive for applied against the motion of the objects. Both these types offer less friction and are primarily described by the type of motion they undergo.

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