Important Topic of Physics: Rolling Friction

Introduction

Each body or object experiences a contact force that always opposes the relative motion between the surfaces whenever the surface of a body slides over another. Such a contact force is known as frictional force. The intermolecular interaction developing due to the elastic properties of matter is the main cause of frictional force. This force acts tangentially to the interface of two objects. Earlier it was thought that the roughness of the two surfaces causes friction because it can be easily seen that the smoother the surfaces, the less the friction. The interlocking of irregularities of the two surfaces causes hindrance to slide.

The information about rolling friction from various physics-related articles is available here. Friction and rolling friction are important topics in physics. Students who want to flourish in physics need to be well known about rolling friction to get deep knowledge about it to do well on their exams. The examples, laws, causes, and coefficient of rolling friction are provided here to assist students in effectively understanding the respective topic. Continue to visit our website for additional physics topics.

Overview

Rolling resistance, also called rolling friction or rolling drag can be defined as the force resisting the movement when a body or object rolls on a surface. The major contributor to rolling resistance is the process called hysteresis. It is essentially the energy loss that occurs as a tire roll through its footprint. The energy loss must be overcome by the vehicle’s engine, which results in wasted fuel. The coefficient of rolling friction depends on the radius of the rolling body, the depth to which the body can sink, and the toughness of the surface. Whereas the coefficient of sliding friction depends on the texture of the surface and temperature to a certain limit. It is independent of all other external factors. If the surface is rolling the area of interaction between the base and the surface will be very less hence rolling friction will be less than sliding friction as interlocking is less. So, sliding friction is greater than rolling friction. In real life, sports like cricket, soccer, and baseball make use of rolling friction. Also, a few sports like curling, carom are based on sliding friction.

Rolling Friction

In general, friction is the force that resists the motion of a solid body over another. Friction is very important to our world because it affects everything that’s in motion. The friction is acting in the opposite direction when an object is moving, slipping, or sliding in one direction. There are different types of friction including rolling friction and sliding friction. The force due to friction doesn’t necessarily act to resist the movement of the object but acts to oppose slipping or sliding along the contact surface. That is, an object can roll without slipping. The object will roll when its center of gravity is not above its base of support. The force that opposes the movement of a rolling object on a surface is called rolling friction. It is also known as rolling resistance and is similar to kinetic friction. It is a little weaker than sliding friction. Rolling friction is applicable for objects whose point of contact keeps changing.

The examples of rolling friction are:

• The rolling of a football on the ground.
• The motion of a truck wheel on the ground.

We can say a ball rolling on a field will travel less than a ball on a concrete floor since the friction on the former surface will be larger.

Laws of Rolling Friction

The three laws of rolling friction:

(1) With the increase in smoothness, the force of rolling friction reduces.

(2) Rolling friction can be written as a product of load and constant to the given fractional power.

(3) The rolling friction force is inversely proportional to the curvature radius and it is directly proportional to load.

Causes of Rolling Friction

When given objects or bodies are rolled onto a surface, following things will happen:

• The body is usually deformed at the point of contact with the present surface.
• The motion is often created below the surface as the result of the above-mentioned points.

The primary and major cause of this rolling friction is that the energy of deformation is greater than that of the energy of recovery. And there is an adhesive force present between the two surfaces which needs to be overcome constantly.

The factors affecting rolling friction are:

• The sliding body (object) quality
• The surface Load quality
• The rolling object diameter
• The body (object) surface area

Coefficient of Rolling Friction

Determining the coefficient of rolling friction is basically more complex than that of sliding friction.

The coefficient of Rolling Friction can be expressed as a given ratio of the force of rolling friction to the total weight of that object.

The coefficient of rolling resistance in empirical terms can be written as:

Here, F_r is the resistive force of rolling resistance.

is the coefficient of rolling resistance.

is the weight of the rolling object.

Also read: Multiplication of Vectors by a Real Number

Frequently Asked Question (FAQs):

Question 1: What are the two types of friction?

Answer: The two types of friction are rolling friction and sliding friction.

Question 2: What is meant by rolling friction?

Answer: Rolling Friction is the force that resists the movement of a rolling body on a surface. It is also known as the rolling resistance.

Question 3: What is the coefficient of rolling resistance?

Answer: The coefficient of rolling resistance is µr.

Question 4: What is the example of rolling friction?

Answer: If a basketball rolled on the court, it would eventually come to a halt.

Question 5: Does speed affect rolling friction?

Answer: Factors that contribute to rolling resistance include deformation of the wheels, the deformation of the roadbed surface, and movement below the surface. So, it is clear that the rolling resistance factor is not dependent on speed.

Question 6: What areas do rolling friction depend on?

Answer: They are as follows:

• The shape of the wheel or curved surface.
• The nature of the rolling surface.
• Wheel speed.
• Type of tire material or curved surface.