Rolling Friction: Overview, Questions, Preparation

The fluid friction acts as the resistance between the relative motion of the surface, materials sliding against each other, and the layers of the fluids. It resists the motion acting between the surfaces.

The types of friction are listed below:

1. Dry friction – It resists the lateral motion between the connect of two surfaces
2. Fluid friction – It resists the relative motion between the layers of the fluid
3. Lubricated friction – It is a part of fluid friction; only the separation of two surfaces takes place with a lubricant fluid
4. Skin friction – The force that acts between the solid surfaces resist the motion of the fluid across the skin's surface
5. Internal Friction – This force resists the motion of deformation

The Rolling Friction is described as the force resisting the motion of two rolling surfaces of the objects. Examples of Rolling Friction are rolling of a ball, cart trolley in supermarkets, wheel on the ground, etc. Rolling Friction is somewhat weaker than Sliding Friction.

The factors that affect the Rolling Friction are as follows:

• Load
• Diameter of object
• Surface area
• The surface's quality
• And the quality of the sliding object

The Rolling Friction has three laws that are as follows:

1. The first law of Rolling Friction states that a smooth surface decreases the force of it
2. The Rolling Friction shows the relation between load and constant that is expressed below:

F = kLn

3. It is inversely proportional to the radius of the curvature and directly proportional to load; it can be written as:

F = u x W / r

The coefficient of Rolling Friction can be described as the relationship between the force of rolling friction and the total weight of the object. It can be written as:

• Fr = urW
• Here, the resistive force is denoted as Fr
• The weight of the body is denoted as W
• And the coefficient of rolling resistance is denoted as UR

Rolling Friction for Class 11

The chapter 'Friction' holds a weightage of a significant 14 marks. The chapter is very important as per the new pattern of 2021. It includes six questions in total, consisting of two objective type questions, two very short questions, one short, and one long question.

Example 1) Write the coefficient of Rolling Friction.

Answer – The coefficient of Rolling Friction is Fr = urW.

Example 2) Write the examples of Rolling Friction.

Answer – The examples of Rolling Friction are rolling of a ball, cart trolley in supermarkets, wheel on the ground, etc.

Example 3) State the Third Law of Rolling Friction.

Answer – The Third Law of Rolling Friction states that the rolling friction is inversely proportional to the radius of the curvature and directly proportional to load, it can be written as: F = u x W / r.

Q: What do you mean by Rolling Friction?

Q: What is the coefficient of Rolling Friction?

Q: What is the first law of Rolling Friction?

Q: What are the factors that cause the friction?

Q: What is the second law of the Rolling Friction?