Rolling friction, also known as rolling resistance, is the force that opposes the motion of a rolling object on a surface. It occurs when an object, such as a wheel or a ball, moves by rotating on a surface, and the resistance to its motion is due to the deformation and interaction between the object and the surface.
The formula for rolling friction force (Fr) is often expressed as:
Fr=μrN
Where:
- Fr is the rolling friction force,
- μr is the coefficient of rolling friction (a dimensionless constant),
- N is the normal force between the rolling object and the surface.
Coefficient of Rolling Friction
Determining the coefficient of rolling friction is more intricate compared to sliding friction.
The coefficient of rolling friction is defined as the ratio of the force of rolling friction to the total weight of the object.
In empirical terms, the coefficient of rolling resistance can be expressed as:
Fr = μr W
where,
- Fr is the resistive force of rolling resistance
- μr is the coefficient of rolling resistance
- W is the weight of the rolling body
Daily Life Examples of Rolling Friction
- Car tires on the road
- Bicycle riding
- Ball rolling on the ground
- Office chair wheels
- Luggage with wheels
- Roller skating
- Caster wheels on furniture
- Sports balls on playing fields
