# Rolling Friction and Rolling Resistance

PhysicsFriction

#### Class 11th Physics - Elasticity

6 Lectures 1 hours

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12 Lectures 2 hours

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14 Lectures 3 hours

## Introduction

Rolling friction and rolling resistance refer to the force that helps to resist the rolling motion of the machinery body of the surface. For example, it is commonly seen that pulling a heavy almirah on a rough surface is so tough but if an iron wheel is used then the pulling, the process becomes easier. It has happened just because iron wheels do not slide on the floor but roll on the floor. The velocity of the point of the wheel with the floor remains zero and that is why the iron wheel proceeds smoothly on the floor.

## What is rolling friction?

The rolling friction is the force that helps to resist as well as slow down a wheel’s motion on the curved or rough surface. Sliding or slipping an object on a surface takes a lot of time and energy compared to rolling (Acary & Bourrier, 2021). Rolling friction refers to a weaker force that explains the reason the pulling a heavy object on a rough surface.

Figure 1: The expression of the rolling friction

Several types of friction are commonly seen like static and sliding friction. The static friction denotes the type of frictional force, which acts between the surface during the resting period with respect to other objects while the sliding friction can be defined as the resistance that is generated between two different objects during sliding (Xie, Ma & Zhao, 2019). Examples of static friction are the resting period of the table lamp on a table and generating heat by running palms together. An example of sliding friction is sliding a block on the floor.

## What is rolling resistance?

Rolling resistance refers to the energy which is essential for a wheel to maintain the smooth movement maintaining consistency with the speed. It is just the opposite action of rolling that happens during the rolling of an object in the motion and it starts when it brings in contact with the surface (Hanisch & Ziese, 2021). The energy that is required for providing the resistance of a rolling object is recoverable.

### The formula of rolling friction and rolling resistance

Figure 2: The rolling resistance

The formula of the rolling friction is $\mathrm{F\:=\:μ_rN}$, where the F stands for the rolling friction that is dependent on some value or the object and surface. In this formula, μr signifies the coefficient relation of the rolling friction of an object on the surface and N denotes the normal reaction that is commonly seen on the objects (Xie, Ma & Zhao, 2019). The factors that signify the rolling friction of an object are the shape of the state of the surface, the nature of the rolling surface and the wheel’s speed (Liu, Liu & Mao, 2018). Besides this, the rolling friction also relies on the wheel’s radius and material consistency of the objects as well as the surface.

## The application of rolling friction and rolling resistance

The application of the rolling friction as well as the rolling resistance can be seen during the movement of a car on the road and then the friction of the car’s wheel and the read surface originate friction that creates a resistance to stop the car (Hanisch & Ziese, 2021). Besides this, a larger wheel of a car creates more resistance compared to another car’s wheels.

Figure 3: Rolling friction and Rolling resistance

On the train line, passing a train is a superior example of the rolling friction that guides to create a great rolling resistance power. “F = k * Ln” is the most significant formula that denotes rolling friction with the multiplication of the load as well as the fractional power that is constant (Liu, Liu & Mao, 2018). In this formula, F stands for rolling friction that depends on K which denotes the constant power of fraction with the multiplication of the total load of the object that signifies the litter of L.

## Conclusion

The rolling friction creates resistance to the speed and the motion of the moving objects on the floor. The “rolling resistance resistivity” of an object is entirely dependent on the body weight of the object, which is in a rolling motion, and the “coefficient of rolling resistance”. Besides this, the body mass and the gravitational acceleration of the object are also considered as the core components of the rolling objects that provide resistance to the objects on the surface. The length dimension of the rolling objects is another significant factor of rolling friction that maintains the rate of rolling friction.

## FAQs

Q1. What are the factors that create disturbance for the rolling resistance of a vehicle?

Ans. The diameter and the pressure of the wheel create disturbance for the rolling resistance of a vehicle. Besides this, the construction, width and tread of the wheel has also a great impact on the rolling resistance of an object.

Q2. What are the factors that affect the rolling friction?

Ans. Some factors greatly affect the rate of rolling friction like the speed as well as the radius of the car or wheel. Besides this, the wheel’s shape and the nature or states of the surface have a great impact on the rate of the curved surface.

Q3. Which components reduce the rate of rolling friction?

Ans. The elastic diameter of the wheel and the irregularities of the surface have a great influence on the rolling friction of the wheel. Molecular friction is another core component that also affects the rolling friction significantly.

Q4. What is the rolling resistance force?

Ans. Rolling resistance is the power of resistance that mainly occurs during the rolling of a round object on a surface like a ball, wheel as well as a cylinder. The principal reason for rolling resistance is the deformation of the particular object as well as surface deformation or in both cases, the resistance can be seen.

Updated on 13-Oct-2022 11:19:47